STM32F042x4 STM32F042x6 ARM(R)-based 32-bit MCU, up to 32 KB Flash, crystal-less USB FS 2.0, CAN, 9 timers, ADC and comm. interfaces, 2.0 - 3.6 V Datasheet - production data Features * Core: ARM(R) 32-bit Cortex(R)-M0 CPU, frequency up to 48 MHz LQFP48 7x7 mm LQFP32 7x7 mm * Memories - 16 to 32 Kbytes of Flash memory - 6 Kbytes of SRAM with HW parity * CRC calculation unit * Reset and power management - Digital and I/Os supply: VDD = 2 V to 3.6 V - Analog supply: VDDA = from VDD to 3.6 V - Selected I/Os: VDDIO2 = 1.65 V to 3.6 V - Power-on/Power down reset (POR/PDR) - Programmable voltage detector (PVD) - Low power modes: Sleep, Stop, Standby - VBAT supply for RTC and backup registers * Clock management - 4 to 32 MHz crystal oscillator - 32 kHz oscillator for RTC with calibration - Internal 8 MHz RC with x6 PLL option - Internal 40 kHz RC oscillator - Internal 48 MHz oscillator with automatic trimming based on ext. synchronization * Up to 38 fast I/Os - All mappable on external interrupt vectors - Up to 24 I/Os with 5 V tolerant capability and 8 with independent supply VDDIO2 * 5-channel DMA controller * One 12-bit, 1.0 s ADC (up to 10 channels) - Conversion range: 0 to 3.6 V - Separate analog supply: 2.4 V to 3.6 V * Up to 14 capacitive sensing channels for touchkey, linear and rotary touch sensors * Calendar RTC with alarm and periodic wakeup from Stop/Standby January 2017 This is information on a product in full production. UFQFPN48 7x7 mm WLCSP36 UFQFPN32 5x5 mm 2.6x2.7 mm UFQFPN28 4x4 mm TSSOP20 6.5x4.4 mm * Nine timers - One 16-bit advanced-control timer for six channel PWM output - One 32-bit and four 16-bit timers, with up to four IC/OC, OCN, usable for IR control decoding - Independent and system watchdog timers - SysTick timer * Communication interfaces - One I2C interface supporting Fast Mode Plus (1 Mbit/s) with 20 mA current sink, SMBus/PMBus and wakeup - Two USARTs supporting master synchronous SPI and modem control, one with ISO7816 interface, LIN, IrDA, auto baud rate detection and wakeup feature - Two SPIs (18 Mbit/s) with 4 to 16 programmable bit frames, one with I2S interface multiplexed - CAN interface - USB 2.0 full-speed interface, able to run from internal 48 MHz oscillator and with BCD and LPM support * HDMI CEC, wakeup on header reception * Serial wire debug (SWD) * 96-bit unique ID * All packages ECOPACK(R)2 Table 1. Device summary Reference Part number STM32F042x4 STM32F042F4, STM32F042G4, STM32F042K4, STM32F042T4, STM32F042C4 STM32F042x6 STM32F042F6, STM32F042G6, STM32F042K6, STM32F042T6, STM32F042C6 DocID025832 Rev 5 1/117 www.st.com Contents STM32F042x4 STM32F042x6 Contents 1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3 Functional overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.1 ARM(R)-Cortex(R)-M0 core . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.2 Memories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.3 Boot modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.4 Cyclic redundancy check calculation unit (CRC) . . . . . . . . . . . . . . . . . . . 14 3.5 Power management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Power supply schemes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.5.2 Power supply supervisors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3.5.3 Voltage regulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.5.4 Low-power modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.6 Clocks and startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 3.7 General-purpose inputs/outputs (GPIOs) . . . . . . . . . . . . . . . . . . . . . . . . . 17 3.8 Direct memory access controller (DMA) . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.9 Interrupts and events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.10 2/117 3.5.1 3.9.1 Nested vectored interrupt controller (NVIC) . . . . . . . . . . . . . . . . . . . . . . 18 3.9.2 Extended interrupt/event controller (EXTI) . . . . . . . . . . . . . . . . . . . . . . 18 Analog-to-digital converter (ADC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3.10.1 Temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.10.2 Internal voltage reference (VREFINT) . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3.10.3 VBAT battery voltage monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.11 Touch sensing controller (TSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3.12 Timers and watchdogs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.12.1 Advanced-control timer (TIM1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 3.12.2 General-purpose timers (TIM2, 3, 14, 16, 17) . . . . . . . . . . . . . . . . . . . . 22 3.12.3 Independent watchdog (IWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.12.4 System window watchdog (WWDG) . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.12.5 SysTick timer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 3.13 Real-time clock (RTC) and backup registers . . . . . . . . . . . . . . . . . . . . . . 23 3.14 Inter-integrated circuit interface (I2C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Contents 3.15 Universal synchronous/asynchronous receiver/transmitter (USART) . . . 25 3.16 Serial peripheral interface (SPI) / Inter-integrated sound interface (I2S) . 26 3.17 High-definition multimedia interface (HDMI) - consumer electronics control (CEC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.18 Controller area network (CAN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3.19 Universal serial bus (USB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.20 Clock recovery system (CRS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.21 Serial wire debug port (SW-DP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4 Pinouts and pin descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 5 Memory mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 6 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 6.1 Parameter conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 6.1.1 Minimum and maximum values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 6.1.2 Typical values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 6.1.3 Typical curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 6.1.4 Loading capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 6.1.5 Pin input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 6.1.6 Power supply scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 6.1.7 Current consumption measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 6.2 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 6.3 Operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 6.3.1 General operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 6.3.2 Operating conditions at power-up / power-down . . . . . . . . . . . . . . . . . . 47 6.3.3 Embedded reset and power control block characteristics . . . . . . . . . . . 48 6.3.4 Embedded reference voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 6.3.5 Supply current characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 6.3.6 Wakeup time from low-power mode . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 6.3.7 External clock source characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 6.3.8 Internal clock source characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 6.3.9 PLL characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 6.3.10 Memory characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 6.3.11 EMC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 6.3.12 Electrical sensitivity characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 DocID025832 Rev 5 3/117 4 Contents 7 STM32F042x4 STM32F042x6 6.3.13 I/O current injection characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.3.14 I/O port characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 6.3.15 NRST pin characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 6.3.16 12-bit ADC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 6.3.17 Temperature sensor characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 6.3.18 VBAT monitoring characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 6.3.19 Timer characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 6.3.20 Communication interfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 7.1 LQFP48 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 7.2 UFQFPN48 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 7.3 WLCSP36 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 7.4 LQFP32 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 7.5 UFQFPN32 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 7.6 UFQFPN28 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 7.7 TSSOP20 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 7.8 Thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 7.8.1 Reference document . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 7.8.2 Selecting the product temperature range . . . . . . . . . . . . . . . . . . . . . . 111 8 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 9 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 4/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 List of tables List of tables Table 1. Table 2. Table 3. Table 4. Table 5. Table 6. Table 7. Table 8. Table 9. Table 10. Table 11. Table 12. Table 13. Table 14. Table 15. Table 16. Table 17. Table 18. Table 19. Table 20. Table 21. Table 22. Table 23. Table 24. Table 25. Table 26. Table 27. Table 28. Table 29. Table 30. Table 31. Table 32. Table 33. Table 34. Table 35. Table 36. Table 37. Table 38. Table 39. Table 40. Table 41. Table 42. Table 43. Table 44. Table 45. Table 46. Table 47. Device summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 STM32F042x4/x6 device features and peripheral counts . . . . . . . . . . . . . . . . . . . . . . . . . 11 Temperature sensor calibration values. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Internal voltage reference calibration values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 Capacitive sensing GPIOs available on STM32F042x4/x6 devices . . . . . . . . . . . . . . . . . . 20 No. of capacitive sensing channels available on STM32F042x devices. . . . . . . . . . . . . . . 21 Timer feature comparison . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Comparison of I2C analog and digital filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 STM32F042x4/x6 I2C implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 STM32F042x4/x6 USART implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 STM32F042x4/x6 SPI/I2S implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 Legend/abbreviations used in the pinout table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 STM32F042x pin definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Alternate functions selected through GPIOA_AFR registers for port A . . . . . . . . . . . . . . . 37 Alternate functions selected through GPIOB_AFR registers for port B . . . . . . . . . . . . . . . 38 Alternate functions selected through GPIOF_AFR registers for port F. . . . . . . . . . . . . . . . 38 STM32F042x4/x6 peripheral register boundary addresses . . . . . . . . . . . . . . . . . . . . . . . . 40 Voltage characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Current characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Thermal characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 General operating conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Operating conditions at power-up / power-down . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Embedded reset and power control block characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . 48 Programmable voltage detector characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Embedded internal reference voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Typical and maximum current consumption from VDD supply at VDD = 3.6 V . . . . . . . . . . 50 Typical and maximum current consumption from the VDDA supply . . . . . . . . . . . . . . . . . 52 Typical and maximum consumption in Stop and Standby modes . . . . . . . . . . . . . . . . . . . 53 Typical and maximum current consumption from the VBAT supply. . . . . . . . . . . . . . . . . . . 54 Typical current consumption, code executing from Flash memory, running from HSE 8 MHz crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 Switching output I/O current consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 Peripheral current consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Low-power mode wakeup timings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 High-speed external user clock characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Low-speed external user clock characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 HSE oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 LSE oscillator characteristics (fLSE = 32.768 kHz) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 HSI oscillator characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 HSI14 oscillator characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 HSI48 oscillator characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 LSI oscillator characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 PLL characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Flash memory characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 Flash memory endurance and data retention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 EMS characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 EMI characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 ESD absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 DocID025832 Rev 5 5/117 6 List of tables Table 48. Table 49. Table 50. Table 51. Table 52. Table 53. Table 54. Table 55. Table 56. Table 57. Table 58. Table 59. Table 60. Table 61. Table 62. Table 63. Table 64. Table 65. Table 66. Table 67. Table 68. Table 69. Table 70. Table 71. Table 72. Table 73. Table 74. Table 75. Table 76. 6/117 STM32F042x4 STM32F042x6 Electrical sensitivities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 I/O current injection susceptibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 I/O static characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 Output voltage characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 I/O AC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76 NRST pin characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 ADC characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 RAIN max for fADC = 14 MHz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 ADC accuracy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 TS characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 VBAT monitoring characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 TIMx characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 IWDG min/max timeout period at 40 kHz (LSI). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 WWDG min/max timeout value at 48 MHz (PCLK). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 I2C analog filter characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 SPI characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 I2S characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 USB electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 LQFP48 package mechanical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 UFQFPN48 package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 WLCSP36 package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 WLCSP36 recommended PCB design rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 LQFP32 package mechanical data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 UFQFPN32 package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 UFQFPN28 package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 TSSOP20 package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Package thermal characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 Ordering information scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Document revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 DocID025832 Rev 5 STM32F042x4 STM32F042x6 List of figures List of figures Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. Figure 7. Figure 8. Figure 9. Figure 10. Figure 11. Figure 12. Figure 13. Figure 14. Figure 15. Figure 16. Figure 17. Figure 18. Figure 19. Figure 20. Figure 21. Figure 22. Figure 23. Figure 24. Figure 25. Figure 26. Figure 27. Figure 28. Figure 29. Figure 30. Figure 31. Figure 32. Figure 33. Figure 34. Figure 35. Figure 36. Figure 37. Figure 38. Figure 39. Figure 40. Figure 41. Figure 42. Figure 43. Figure 44. Figure 45. Figure 46. Figure 47. Figure 48. Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Clock tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 LQFP48 package pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 UFQFPN48 package pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 WLCSP36 package pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 LQFP32 package pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 UFQFPN32 package pinout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 UFQFPN28 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 TSSOP20 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 STM32F042x6 memory map . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Pin loading conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Pin input voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Power supply scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Current consumption measurement scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 High-speed external clock source AC timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Low-speed external clock source AC timing diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 Typical application with an 8 MHz crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 Typical application with a 32.768 kHz crystal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 HSI oscillator accuracy characterization results for soldered parts . . . . . . . . . . . . . . . . . . 65 HSI14 oscillator accuracy characterization results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 HSI48 oscillator accuracy characterization results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 TC and TTa I/O input characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 Five volt tolerant (FT and FTf) I/O input characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 I/O AC characteristics definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77 Recommended NRST pin protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 ADC accuracy characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Typical connection diagram using the ADC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 SPI timing diagram - slave mode and CPHA = 0 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 SPI timing diagram - slave mode and CPHA = 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 SPI timing diagram - master mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 I2S slave timing diagram (Philips protocol) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 I2S master timing diagram (Philips protocol). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 LQFP48 package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 Recommended footprint for LQFP48 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 LQFP48 package marking example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 UFQFPN48 package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 Recommended footprint for UFQFPN48 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 UFQFPN48 package marking example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 WLCSP36 package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 Recommended pad footprint for WLCSP36 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97 WLCSP36 package marking example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 LQFP32 package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 Recommended footprint for LQFP32 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 LQFP32 package marking example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 UFQFPN32 package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Recommended footprint for UFQFPN32 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 UFQFPN32 package marking example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 UFQFPN28 package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 DocID025832 Rev 5 7/117 8 List of figures Figure 49. Figure 50. Figure 51. Figure 52. Figure 53. 8/117 STM32F042x4 STM32F042x6 Recommended footprint for UFQFPN28 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 UFQFPN28 package marking example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 TSSOP20 package outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108 Recommended footprint for TSSOP20 package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109 TSSOP20 package marking example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 DocID025832 Rev 5 STM32F042x4 STM32F042x6 1 Introduction Introduction This datasheet provides the ordering information and mechanical device characteristics of the STM32F042x4/x6 microcontrollers. This document should be read in conjunction with the STM32F0xxxx reference manual (RM0091). The reference manual is available from the STMicroelectronics website www.st.com. For information on the ARM(R) Cortex(R)-M0 core, please refer to the Cortex(R)-M0 Technical Reference Manual, available from the www.arm.com website. DocID025832 Rev 5 9/117 27 Description 2 STM32F042x4 STM32F042x6 Description The STM32F042x4/x6 microcontrollers incorporate the high-performance ARM(R) Cortex(R)-M0 32-bit RISC core operating at up to 48 MHz frequency, high-speed embedded memories (up to 32 Kbytes of Flash memory and 6 Kbytes of SRAM), and an extensive range of enhanced peripherals and I/Os. All devices offer standard communication interfaces (one I2C, two SPIs/one I2S, one HDMI CEC and two USARTs), one USB Full-speed device (crystal-less), one CAN, one 12-bit ADC, four 16-bit timers, one 32-bit timer and an advanced-control PWM timer. The STM32F042x4/x6 microcontrollers operate in the -40 to +85 C and -40 to +105 C temperature ranges, from a 2.0 to 3.6 V power supply. A comprehensive set of power-saving modes allows the design of low-power applications. The STM32F042x4/x6 microcontrollers include devices in seven different packages ranging from 20 pins to 48 pins with a die form also available upon request. Depending on the device chosen, different sets of peripherals are included. These features make the STM32F042x4/x6 microcontrollers suitable for a wide range of applications such as application control and user interfaces, hand-held equipment, A/V receivers and digital TV, PC peripherals, gaming and GPS platforms, industrial applications, PLCs, inverters, printers, scanners, alarm systems, video intercoms and HVACs. 10/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Description Table 2. STM32F042x4/x6 device features and peripheral counts Peripheral Flash memory (Kbyte) STM32F042Fx 16 32 STM32F042G 16 STM32F042K 32 16 SRAM (Kbyte) Timers 16 32 STM32F042C 16 32 6 Advanced control 1 (16-bit) General purpose 4 (16-bit) 1 (32-bit) SPI [I2S](1) Comm. interfaces 32 STM32F042T 1 [1] 2 [1] 2 I C 1 USART 2 CAN 1 USB 1 CEC 1 12-bit ADC (number of channels) 1 (9 ext. + 3 int.) 1 (10 ext. + 3 int.) GPIOs 16 24 26 28 30 38 Capacitive sensing channels 7 11 13 14 14 14 Max. CPU frequency 48 MHz Operating voltage 2.0 to 3.6 V Operating temperature Ambient operating temperature: -40C to 85C / -40C to 105C Junction temperature: -40C to 105C / -40C to 125C Packages TSSOP20 UQFPN28 LQFP32 UQFPN32 WLCSP36 LQFP48 UFQFPN48 1. The SPI interfaces can be used either in SPI mode or in I2S audio mode. DocID025832 Rev 5 11/117 27 Description STM32F042x4 STM32F042x6 Figure 1. Block diagram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ocID025832 Rev 5 STM32F042x4 STM32F042x6 3 Functional overview Functional overview Figure 1 shows the general block diagram of the STM32F042x4/x6 devices. 3.1 ARM(R)-Cortex(R)-M0 core The ARM(R) Cortex(R)-M0 is a generation of ARM 32-bit RISC processors for embedded systems. It has been developed to provide a low-cost platform that meets the needs of MCU implementation, with a reduced pin count and low-power consumption, while delivering outstanding computational performance and an advanced system response to interrupts. The ARM(R) Cortex(R)-M0 processors feature exceptional code-efficiency, delivering the high performance expected from an ARM core, with memory sizes usually associated with 8- and 16-bit devices. The STM32F042x4/x6 devices embed ARM core and are compatible with all ARM tools and software. 3.2 Memories The device has the following features: * 6 Kbytes of embedded SRAM accessed (read/write) at CPU clock speed with 0 wait states and featuring embedded parity checking with exception generation for fail-critical applications. * The non-volatile memory is divided into two arrays: - 16 to 32 Kbytes of embedded Flash memory for programs and data - Option bytes The option bytes are used to write-protect the memory (with 4 KB granularity) and/or readout-protect the whole memory with the following options: - Level 0: no readout protection - Level 1: memory readout protection, the Flash memory cannot be read from or written to if either debug features are connected or boot in RAM is selected (R) Level 2: chip readout protection, debug features (Cortex -M0 serial wire) and boot in RAM selection disabled - 3.3 Boot modes At startup, the boot pin and boot selector option bits are used to select one of the three boot options: * boot from User Flash memory * boot from System Memory * boot from embedded SRAM The boot pin is shared with the standard GPIO and can be disabled through the boot selector option bits. The boot loader is located in System Memory. It is used to reprogram the Flash memory by using USART on pins PA14/PA15, or PA9/PA10 or I2C on pins PB6/PB7 or through the USB DFU interface. DocID025832 Rev 5 13/117 27 Functional overview 3.4 STM32F042x4 STM32F042x6 Cyclic redundancy check calculation unit (CRC) The CRC (cyclic redundancy check) calculation unit is used to get a CRC code from a 32-bit data word and a CRC-32 (Ethernet) polynomial. Among other applications, CRC-based techniques are used to verify data transmission or storage integrity. In the scope of the EN/IEC 60335-1 standard, they offer a means of verifying the Flash memory integrity. The CRC calculation unit helps compute a signature of the software during runtime, to be compared with a reference signature generated at linktime and stored at a given memory location. 3.5 Power management 3.5.1 Power supply schemes * VDD = VDDIO1 = 2.0 to 3.6 V: external power supply for I/Os (VDDIO1) and the internal regulator. It is provided externally through VDD pins. * VDDA = from VDD to 3.6 V: external analog power supply for ADC, Reset blocks, RCs and PLL (minimum voltage to be applied to VDDA is 2.4 V when the ADC is used). It is provided externally through VDDA pin. The VDDA voltage level must be always greater or equal to the VDD voltage level and must be established first. * VDDIO2 = 1.65 to 3.6 V: external power supply for marked I/Os. VDDIO2 is provided externally through the VDDIO2 pin. The VDDIO2 voltage level is completely independent from VDD or VDDA, but it must not be provided without a valid supply on VDD. The VDDIO2 supply is monitored and compared with the internal reference voltage (VREFINT). When the VDDIO2 is below this threshold, all the I/Os supplied from this rail are disabled by hardware. The output of this comparator is connected to EXTI line 31 and it can be used to generate an interrupt. Refer to the pinout diagrams or tables for concerned I/Os list. * VBAT = 1.65 to 3.6 V: power supply for RTC, external clock 32 kHz oscillator and backup registers (through power switch) when VDD is not present. For more details on how to connect power pins, refer to Figure 13: Power supply scheme. 3.5.2 Power supply supervisors The device has integrated power-on reset (POR) and power-down reset (PDR) circuits. They are always active, and ensure proper operation above a threshold of 2 V. The device remains in reset mode when the monitored supply voltage is below a specified threshold, VPOR/PDR, without the need for an external reset circuit. * The POR monitors only the VDD supply voltage. During the startup phase it is required that VDDA should arrive first and be greater than or equal to VDD. * The PDR monitors both the VDD and VDDA supply voltages, however the VDDA power supply supervisor can be disabled (by programming a dedicated Option bit) to reduce the power consumption if the application design ensures that VDDA is higher than or equal to VDD. The device features an embedded programmable voltage detector (PVD) that monitors the VDD power supply and compares it to the VPVD threshold. An interrupt can be generated when VDD drops below the VPVD threshold and/or when VDD is higher than the VPVD 14/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Functional overview threshold. The interrupt service routine can then generate a warning message and/or put the MCU into a safe state. The PVD is enabled by software. 3.5.3 Voltage regulator The regulator has two operating modes and it is always enabled after reset. * Main (MR) is used in normal operating mode (Run). * Low power (LPR) can be used in Stop mode where the power demand is reduced. In Standby mode, it is put in power down mode. In this mode, the regulator output is in high impedance and the kernel circuitry is powered down, inducing zero consumption (but the contents of the registers and SRAM are lost). 3.5.4 Low-power modes The STM32F042x4/x6 microcontrollers support three low-power modes to achieve the best compromise between low power consumption, short startup time and available wakeup sources: * Sleep mode In Sleep mode, only the CPU is stopped. All peripherals continue to operate and can wake up the CPU when an interrupt/event occurs. * Stop mode Stop mode achieves very low power consumption while retaining the content of SRAM and registers. All clocks in the 1.8 V domain are stopped, the PLL, the HSI RC and the HSE crystal oscillators are disabled. The voltage regulator can also be put either in normal or in low power mode. The device can be woken up from Stop mode by any of the EXTI lines. The EXTI line source can be one of the 16 external lines, the PVD output, RTC, I2C1 USART1, USB or the CEC. The CEC, USART1 and I2C1 peripherals can be configured to enable the HSI RC oscillator so as to get clock for processing incoming data. If this is used when the voltage regulator is put in low power mode, the regulator is first switched to normal mode before the clock is provided to the given peripheral. * Standby mode The Standby mode is used to achieve the lowest power consumption. The internal voltage regulator is switched off so that the entire 1.8 V domain is powered off. The PLL, the HSI RC and the HSE crystal oscillators are also switched off. After entering Standby mode, SRAM and register contents are lost except for registers in the RTC domain and Standby circuitry. The device exits Standby mode when an external reset (NRST pin), an IWDG reset, a rising edge on the WKUP pins, or an RTC event occurs. Note: The RTC, the IWDG, and the corresponding clock sources are not stopped by entering Stop or Standby mode. DocID025832 Rev 5 15/117 27 Functional overview 3.6 STM32F042x4 STM32F042x6 Clocks and startup System clock selection is performed on startup, however the internal RC 8 MHz oscillator is selected as default CPU clock on reset. An external 4-32 MHz clock can be selected, in which case it is monitored for failure. If failure is detected, the system automatically switches back to the internal RC oscillator. A software interrupt is generated if enabled. Similarly, full interrupt management of the PLL clock entry is available when necessary (for example on failure of an indirectly used external crystal, resonator or oscillator). Several prescalers allow the application to configure the frequency of the AHB and the APB domains. The maximum frequency of the AHB and the APB domains is 48 MHz. Additionally, also the internal RC 48 MHz oscillator can be selected for system clock or PLL input source. This oscillator can be automatically fine-trimmed by the means of the CRS peripheral using the external synchronization. 16/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Functional overview Figure 2. Clock tree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eneral-purpose inputs/outputs (GPIOs) Each of the GPIO pins can be configured by software as output (push-pull or open-drain), as input (with or without pull-up or pull-down) or as peripheral alternate function. Most of the GPIO pins are shared with digital or analog alternate functions. DocID025832 Rev 5 17/117 27 Functional overview STM32F042x4 STM32F042x6 The I/O configuration can be locked if needed following a specific sequence in order to avoid spurious writing to the I/Os registers. 3.8 Direct memory access controller (DMA) The 5-channel general-purpose DMAs manage memory-to-memory, peripheral-to-memory and memory-to-peripheral transfers. The DMA supports circular buffer management, removing the need for user code intervention when the controller reaches the end of the buffer. Each channel is connected to dedicated hardware DMA requests, with support for software trigger on each channel. Configuration is made by software and transfer sizes between source and destination are independent. DMA can be used with the main peripherals: SPIx, I2Sx, I2Cx, USARTx, all TIMx timers (except TIM14) and ADC. 3.9 Interrupts and events 3.9.1 Nested vectored interrupt controller (NVIC) The STM32F0xx family embeds a nested vectored interrupt controller able to handle up to (R) 32 maskable interrupt channels (not including the 16 interrupt lines of Cortex -M0) and 4 priority levels. * Closely coupled NVIC gives low latency interrupt processing * Interrupt entry vector table address passed directly to the core * Closely coupled NVIC core interface * Allows early processing of interrupts * Processing of late arriving higher priority interrupts * Support for tail-chaining * Processor state automatically saved * Interrupt entry restored on interrupt exit with no instruction overhead This hardware block provides flexible interrupt management features with minimal interrupt latency. 3.9.2 Extended interrupt/event controller (EXTI) The extended interrupt/event controller consists of 24 edge detector lines used to generate interrupt/event requests and wake-up the system. Each line can be independently configured to select the trigger event (rising edge, falling edge, both) and can be masked independently. A pending register maintains the status of the interrupt requests. The EXTI can detect an external line with a pulse width shorter than the internal clock period. Up to 38 GPIOs can be connected to the 16 external interrupt lines. 3.10 Analog-to-digital converter (ADC) The 12-bit analog-to-digital converter has up to 10 external and 3 internal (temperature 18/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Functional overview sensor, voltage reference, VBAT voltage measurement) channels and performs conversions in single-shot or scan modes. In scan mode, automatic conversion is performed on a selected group of analog inputs. The ADC can be served by the DMA controller. An analog watchdog feature allows very precise monitoring of the converted voltage of one, some or all selected channels. An interrupt is generated when the converted voltage is outside the programmed thresholds. 3.10.1 Temperature sensor The temperature sensor (TS) generates a voltage VSENSE that varies linearly with temperature. The temperature sensor is internally connected to the ADC_IN16 input channel which is used to convert the sensor output voltage into a digital value. The sensor provides good linearity but it has to be calibrated to obtain good overall accuracy of the temperature measurement. As the offset of the temperature sensor varies from chip to chip due to process variation, the uncalibrated internal temperature sensor is suitable for applications that detect temperature changes only. To improve the accuracy of the temperature sensor measurement, each device is individually factory-calibrated by ST. The temperature sensor factory calibration data are stored by ST in the system memory area, accessible in read-only mode. Table 3. Temperature sensor calibration values 3.10.2 Calibration value name Description Memory address TS_CAL1 TS ADC raw data acquired at a temperature of 30 C ( 5 C), VDDA= 3.3 V ( 10 mV) 0x1FFF F7B8 - 0x1FFF F7B9 TS_CAL2 TS ADC raw data acquired at a temperature of 110 C ( 5 C), VDDA= 3.3 V ( 10 mV) 0x1FFF F7C2 - 0x1FFF F7C3 Internal voltage reference (VREFINT) The internal voltage reference (VREFINT) provides a stable (bandgap) voltage output for the ADC. VREFINT is internally connected to the ADC_IN17 input channel. The precise voltage of VREFINT is individually measured for each part by ST during production test and stored in the system memory area. It is accessible in read-only mode. Table 4. Internal voltage reference calibration values Calibration value name Description Memory address VREFINT_CAL Raw data acquired at a temperature of 30 C ( 5 C), VDDA= 3.3 V ( 10 mV) 0x1FFF F7BA - 0x1FFF F7BB DocID025832 Rev 5 19/117 27 Functional overview 3.10.3 STM32F042x4 STM32F042x6 VBAT battery voltage monitoring This embedded hardware feature allows the application to measure the VBAT battery voltage using the internal ADC channel ADC_IN18. As the VBAT voltage may be higher than VDDA, and thus outside the ADC input range, the VBAT pin is internally connected to a bridge divider by 2. As a consequence, the converted digital value is half the VBAT voltage. 3.11 Touch sensing controller (TSC) The STM32F042x4/x6 devices provide a simple solution for adding capacitive sensing functionality to any application. These devices offer up to 14 capacitive sensing channels distributed over 5 analog I/O groups. Capacitive sensing technology is able to detect the presence of a finger near a sensor which is protected from direct touch by a dielectric (glass, plastic...). The capacitive variation introduced by the finger (or any conductive object) is measured using a proven implementation based on a surface charge transfer acquisition principle. It consists in charging the sensor capacitance and then transferring a part of the accumulated charges into a sampling capacitor until the voltage across this capacitor has reached a specific threshold. To limit the CPU bandwidth usage, this acquisition is directly managed by the hardware touch sensing controller and only requires few external components to operate. For operation, one capacitive sensing GPIO in each group is connected to an external capacitor and cannot be used as effective touch sensing channel. The touch sensing controller is fully supported by the STMTouch touch sensing firmware library, which is free to use and allows touch sensing functionality to be implemented reliably in the end application. Table 5. Capacitive sensing GPIOs available on STM32F042x4/x6 devices Group 1 2 3 20/117 Capacitive sensing signal name Pin name Capacitive sensing signal name Pin name TSC_G1_IO1 PA0 TSC_G4_IO1 PA9 TSC_G1_IO2 PA1 TSC_G4_IO2 PA10 TSC_G1_IO3 PA2 TSC_G4_IO3 PA11 TSC_G1_IO4 PA3 TSC_G4_IO4 PA12 TSC_G2_IO1 PA4 TSC_G5_IO1 PB3 TSC_G2_IO2 PA5 TSC_G5_IO2 PB4 TSC_G2_IO3 PA6 TSC_G5_IO3 PB6 TSC_G2_IO4 PA7 TSC_G5_IO4 PB7 TSC_G3_IO2 PB0 TSC_G3_IO3 PB1 TSC_G3_IO4 PB2 DocID025832 Rev 5 Group 4 5 STM32F042x4 STM32F042x6 Functional overview Table 6. No. of capacitive sensing channels available on STM32F042x devices Number of capacitive sensing channels STM32F042Cx Analog I/O group LQPF48 STM32F042Tx UQFPN48 WLCSP36 STM32F042Kx LQFP32 UQFPN32 STM32F042Gx STM32F042Fx UQFPN28 TSSOP20 G1 3 3 3 3 3 G2 3 3 3 3 3 G3 2 2 1 2 1 0 G4 3 3 3 1 1 G5 3 3 3 3 0 Number of capacitive sensing channels 14 14 13 14 11 7 3.12 Timers and watchdogs The STM32F042x4/x6 devices include up to five general-purpose timers and an advanced control timer. Table 7 compares the features of the different timers. Table 7. Timer feature comparison Timer type Timer Counter resolution Counter type Prescaler factor DMA request generation Advanced control TIM1 16-bit Up, down, up/down integer from 1 to 65536 Yes 4 3 TIM2 32-bit Up, down, up/down integer from 1 to 65536 Yes 4 - TIM3 16-bit Up, down, up/down integer from 1 to 65536 Yes 4 - TIM14 16-bit Up integer from 1 to 65536 No 1 - TIM16 TIM17 16-bit Up integer from 1 to 65536 Yes 1 1 General purpose 3.12.1 Capture/compare Complementary channels outputs Advanced-control timer (TIM1) The advanced-control timer (TIM1) can be seen as a three-phase PWM multiplexed on six channels. It has complementary PWM outputs with programmable inserted dead times. It DocID025832 Rev 5 21/117 27 Functional overview STM32F042x4 STM32F042x6 can also be seen as a complete general-purpose timer. The four independent channels can be used for: * input capture * output compare * PWM generation (edge or center-aligned modes) * one-pulse mode output If configured as a standard 16-bit timer, it has the same features as the TIMx timer. If configured as the 16-bit PWM generator, it has full modulation capability (0-100%). The counter can be frozen in debug mode. Many features are shared with those of the standard timers which have the same architecture. The advanced control timer can therefore work together with the other timers via the Timer Link feature for synchronization or event chaining. 3.12.2 General-purpose timers (TIM2, 3, 14, 16, 17) There are five synchronizable general-purpose timers embedded in the STM32F042x4/x6 devices (see Table 7 for differences). Each general-purpose timer can be used to generate PWM outputs, or as simple time base. TIM2, TIM3 STM32F042x4/x6 devices feature two synchronizable 4-channel general-purpose timers. TIM2 is based on a 32-bit auto-reload up/downcounter and a 16-bit prescaler. TIM3 is based on a 16-bit auto-reload up/downcounter and a 16-bit prescaler. They feature 4 independent channels each for input capture/output compare, PWM or one-pulse mode output. This gives up to 12 input captures/output compares/PWMs on the largest packages. The TIM2 and TIM3 general-purpose timers can work together or with the TIM1 advancedcontrol timer via the Timer Link feature for synchronization or event chaining. TIM2 and TIM3 both have independent DMA request generation. These timers are capable of handling quadrature (incremental) encoder signals and the digital outputs from 1 to 3 hall-effect sensors. Their counters can be frozen in debug mode. TIM14 This timer is based on a 16-bit auto-reload upcounter and a 16-bit prescaler. TIM14 features one single channel for input capture/output compare, PWM or one-pulse mode output. Its counter can be frozen in debug mode. TIM16 and TIM17 Both timers are based on a 16-bit auto-reload upcounter and a 16-bit prescaler. They each have a single channel for input capture/output compare, PWM or one-pulse mode output. 22/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Functional overview TIM16 and TIM17 have a complementary output with dead-time generation and independent DMA request generation. Their counters can be frozen in debug mode. 3.12.3 Independent watchdog (IWDG) The independent watchdog is based on an 8-bit prescaler and 12-bit downcounter with user-defined refresh window. It is clocked from an independent 40 kHz internal RC and as it operates independently from the main clock, it can operate in Stop and Standby modes. It can be used either as a watchdog to reset the device when a problem occurs, or as a free running timer for application timeout management. It is hardware or software configurable through the option bytes. The counter can be frozen in debug mode. 3.12.4 System window watchdog (WWDG) The system window watchdog is based on a 7-bit downcounter that can be set as free running. It can be used as a watchdog to reset the device when a problem occurs. It is clocked from the APB clock (PCLK). It has an early warning interrupt capability and the counter can be frozen in debug mode. 3.12.5 SysTick timer This timer is dedicated to real-time operating systems, but could also be used as a standard down counter. It features: 3.13 * a 24-bit down counter * autoreload capability * maskable system interrupt generation when the counter reaches 0 * programmable clock source (HCLK or HCLK/8) Real-time clock (RTC) and backup registers The RTC and the five backup registers are supplied through a switch that takes power either on VDD supply when present or through the VBAT pin. The backup registers are five 32-bit registers used to store 20 bytes of user application data when VDD power is not present. They are not reset by a system or power reset, or at wake up from Standby mode. DocID025832 Rev 5 23/117 27 Functional overview STM32F042x4 STM32F042x6 The RTC is an independent BCD timer/counter. Its main features are the following: * calendar with subseconds, seconds, minutes, hours (12 or 24 format), week day, date, month, year, in BCD (binary-coded decimal) format * automatic correction for 28, 29 (leap year), 30, and 31 day of the month * programmable alarm with wake up from Stop and Standby mode capability * on-the-fly correction from 1 to 32767 RTC clock pulses. This can be used to synchronize the RTC with a master clock * digital calibration circuit with 1 ppm resolution, to compensate for quartz crystal inaccuracy * two anti-tamper detection pins with programmable filter. The MCU can be woken up from Stop and Standby modes on tamper event detection * timestamp feature which can be used to save the calendar content. This function can be triggered by an event on the timestamp pin, or by a tamper event. The MCU can be woken up from Stop and Standby modes on timestamp event detection * reference clock detection: a more precise second source clock (50 or 60 Hz) can be used to enhance the calendar precision The RTC clock sources can be: 3.14 * a 32.768 kHz external crystal * a resonator or oscillator * the internal low-power RC oscillator (typical frequency of 40 kHz) * the high-speed external clock divided by 32 Inter-integrated circuit interface (I2C) The I2C interface (I2C1) can operate in multimaster or slave modes. It can support Standard mode (up to 100 kbit/s), Fast mode (up to 400 kbit/s) and Fast Mode Plus (up to 1 Mbit/s) with 20 mA output drive. It supports 7-bit and 10-bit addressing modes, multiple 7-bit slave addresses (two addresses, one with configurable mask). It also includes programmable analog and digital noise filters. Table 8. Comparison of I2C analog and digital filters Aspect Analog filter Digital filter Pulse width of suppressed spikes 50 ns Programmable length from 1 to 15 I2Cx peripheral clocks Benefits Available in Stop mode Drawbacks Variations depending on temperature, voltage, process -Extra filtering capability vs. standard requirements -Stable length Wakeup from Stop on address match is not available when digital filter is enabled. In addition, I2C1 provides hardware support for SMBUS 2.0 and PMBUS 1.1: ARP capability, Host notify protocol, hardware CRC (PEC) generation/verification, timeouts verifications and ALERT protocol management. I2C1 also has a clock domain independent 24/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Functional overview from the CPU clock, allowing the I2C1 to wake up the MCU from Stop mode on address match. The I2C peripheral can be served by the DMA controller. Table 9. STM32F042x4/x6 I2C implementation I2C features(1) I2C1 7-bit addressing mode X 10-bit addressing mode X Standard mode (up to 100 kbit/s) X Fast mode (up to 400 kbit/s) X Fast Mode Plus with 20 mA output drive I/Os (up to 1 Mbit/s) X Independent clock X SMBus X Wakeup from STOP X 1. X = supported. 3.15 Universal synchronous/asynchronous receiver/transmitter (USART) The device embeds two universal synchronous/asynchronous receivers/transmitters (USART1, USART2) which communicate at speeds of up to 6 Mbit/s. They provide hardware management of the CTS, RTS and RS485 DE signals, multiprocessor communication mode, master synchronous communication and single-wire half-duplex communication mode. USART1 supports also SmartCard communication (ISO 7816), IrDA SIR ENDEC, LIN Master/Slave capability and auto baud rate feature, and has a clock domain independent of the CPU clock, allowing to wake up the MCU from Stop mode. The USART interfaces can be served by the DMA controller. Table 10. STM32F042x4/x6 USART implementation USART modes/features(1) USART1 USART2 Hardware flow control for modem X X Continuous communication using DMA X X Multiprocessor communication X X Synchronous mode X X Smartcard mode X - Single-wire half-duplex communication X X IrDA SIR ENDEC block X - LIN mode X - Dual clock domain and wakeup from Stop mode X - Receiver timeout interrupt X - DocID025832 Rev 5 25/117 27 Functional overview STM32F042x4 STM32F042x6 Table 10. STM32F042x4/x6 USART implementation (continued) USART modes/features(1) USART1 USART2 Modbus communication X - Auto baud rate detection X - Driver Enable X X 1. X = supported. 3.16 Serial peripheral interface (SPI) / Inter-integrated sound interface (I2S) Up to two SPIs are able to communicate up to 18 Mbit/s in slave and master modes in fullduplex and half-duplex communication modes. The 3-bit prescaler gives 8 master mode frequencies and the frame size is configurable from 4 bits to 16 bits. One standard I2S interface (multiplexed with SPI1) supporting four different audio standards can operate as master or slave at half-duplex communication mode. It can be configured to transfer 16 and 24 or 32 bits with 16-bit or 32-bit data resolution and synchronized by a specific signal. Audio sampling frequency from 8 kHz up to 192 kHz can be set by an 8-bit programmable linear prescaler. When operating in master mode, it can output a clock for an external audio component at 256 times the sampling frequency. Table 11. STM32F042x4/x6 SPI/I2S implementation SPI features(1) SPI1 SPI2 Hardware CRC calculation X X Rx/Tx FIFO X X NSS pulse mode X X I2S X - X X mode TI mode 1. X = supported. 3.17 High-definition multimedia interface (HDMI) - consumer electronics control (CEC) The device embeds a HDMI-CEC controller that provides hardware support for the Consumer Electronics Control (CEC) protocol (Supplement 1 to the HDMI standard). This protocol provides high-level control functions between all audiovisual products in an environment. It is specified to operate at low speeds with minimum processing and memory overhead. It has a clock domain independent from the CPU clock, allowing the HDMI_CEC controller to wakeup the MCU from Stop mode on data reception. 3.18 Controller area network (CAN) The CAN is compliant with specifications 2.0A and B (active) with a bit rate up to 1 Mbit/s. It can receive and transmit standard frames with 11-bit identifiers as well as extended frames 26/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Functional overview with 29-bit identifiers. It has three transmit mailboxes, two receive FIFOs with 3 stages and 14 scalable filter banks. 3.19 Universal serial bus (USB) The STM32F042x4/x6 embeds a full-speed USB device peripheral compliant with the USB specification version 2.0. The internal USB PHY supports USB FS signaling, embedded DP pull-up and also battery charging detection according to Battery Charging Specification Revision 1.2. The USB interface implements a full-speed (12 Mbit/s) function interface with added support for USB 2.0 Link Power Management. It has software-configurable endpoint setting with packet memory up-to 1 KB (the last 256 byte are used for CAN peripheral if enabled) and suspend/resume support. It requires a precise 48 MHz clock which can be generated from the internal main PLL (the clock source must use an HSE crystal oscillator) or by the internal 48 MHz oscillator in automatic trimming mode. The synchronization for this oscillator can be taken from the USB data stream itself (SOF signalization) which allows crystal-less operation. 3.20 Clock recovery system (CRS) The STM32F042x4/x6 embeds a special block which allows automatic trimming of the internal 48 MHz oscillator to guarantee its optimal accuracy over the whole device operational range. This automatic trimming is based on the external synchronization signal, which could be either derived from USB SOF signalization, from LSE oscillator, from an external signal on CRS_SYNC pin or generated by user software. For faster lock-in during startup it is also possible to combine automatic trimming with manual trimming action. 3.21 Serial wire debug port (SW-DP) An ARM SW-DP interface is provided to allow a serial wire debugging tool to be connected to the MCU. DocID025832 Rev 5 27/117 27 Pinouts and pin descriptions 4 STM32F042x4 STM32F042x6 Pinouts and pin descriptions 3$ 3$ 3$ 3$ 3$ 3% 3% 3% 3% 3% 966 9'' 9'',2 966 3$ 3$ 3$ 3$ 3$ 3$ 3% 3% 3% 3% /4)3 9%$7 3& 3&26&B,1 3&26&B287 3)26&B,1 3)26&B287 1567 966$ 9''$ 3$ 3$ 3$ 7RSYLHZ 9'' 966 3% 3% 3)%227 3% 3% 3% 3% 3% 3$ 3$ Figure 3. LQFP48 package pinout ,2VXSSOLHGIURP9'',2 06Y9 9'' 966 3% 3% 3)%227 3% 3% 3% 3% 3% 3$ 3$ Figure 4. UFQFPN48 package pinout 7RSYLHZ 9%$7 9'',2 3& 966 3&26&B,1 3$ 3&26&B287 3$ 3)26&B,1 3$ 3)26&B287 3$ 1567 3$ 966$ 3$ 9''$ 3% 3$ 3% 3$ 3% 3$ 3% 8)4)31 3$ 3$ 3$ 3$ 3$ 3% 3% 3% 3% 3% 966 9'' ([SRVHGSDG ,2VXSSOLHGIURP9'',2 06Y9 28/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Pinouts and pin descriptions Figure 5. WLCSP36 package pinout 7RSYLHZ $ 3$ 3$ 3% 3% 9'' 3& % 3$ 3$ 3% 3% %227 3& 3) 26&B 26&B ,1 ,1 & 3$ 3$ 3$ 3% 3) 3& 26&B 26&B 287 287 ' 3$ 3% 3$ 3$ 1567 966 ( 9'',2 3$ 3$ 3$ 9''$ 3% ) 966 3% 3% 3$ 3$ 3$ :/&63 ,2VXSSOLHGIURP9'',2 06Y9 1. The above figure shows the package in top view, changing from bottom view in the previous document versions. /4)3 3$ 3$ 3$ 3$ 3$ 3$ 3$ 9'',2 3$ 3$ 3$ 3$ 3$ 3% 3% 966 9'' 3)26&B,1 3)26&B287 1567 9''$ 3$ 3$ 3$ 7RSYLHZ 966 3%%227 3% 3% 3% 3% 3% 3$ Figure 6. LQFP32 package pinout ,2VXSSOLHGIURP9'',2 DocID025832 Rev 5 06Y9 29/117 38 Pinouts and pin descriptions STM32F042x4 STM32F042x6 8)4)31 ([SRVHGSDG 3$ 3$ 3$ 3$ 3$ 3$ 3$ 9'',2 9'' 3)26&B,1 3)26&B287 1567 9''$ 3$ 3$ 3$ 7RSYLHZ 3% 3)%227 3% 3% 3% 3% 3% 3$ Figure 7. UFQFPN32 package pinout 3$ 3$ 3$ 3$ 3$ 3% 3% 3% 966 ,2VXSSOLHGIURP9'',2 06Y9 Figure 8. UFQFPN28 package 8)4)31 3$ 3$>3$@ 3$>3$@ 9'',2 9'' 966 3% 3$ 3$ 3$ 3$ 3$ 3$ 3% 3%%227 3)26&B,1 3)26&B287 1567 9''$ 3$ 3$ 3% 3% 3% 3% 3% 3$ 3$ 7RSYLHZ ,2VXSSOLHGIURP9'',2 06Y9 1. Pin pair PA11/12 can be remapped in place of pin pair PA9/10 using the SYSCFG_CFGR1 register. 30/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Pinouts and pin descriptions Figure 9. TSSOP20 package 7RSYLHZ 76623 3%%227 3)26&B,1 3)26&B287 1567 9''$ 3$ 3$ 3$ 3$ 3$ 3$ 3$ 3$>3$@ 3$>3$@ 9'' 966 3% 3$ 3$ 3$ 06Y9 1. Pin pair PA11/12 can be remapped in place of pin pair PA9/10 using the SYSCFG_CFGR1 register. Table 12. Legend/abbreviations used in the pinout table Name Pin name Abbreviation Unless otherwise specified in brackets below the pin name, the pin function during and after reset is the same as the actual pin name S Pin type I/O structure Pin functions Supply pin I/O Input / output pin FT 5 V-tolerant I/O FTf 5 V-tolerant I/O, FM+ capable TTa 3.3 V-tolerant I/O directly connected to ADC TC Standard 3.3 V I/O RST Notes Definition Bidirectional reset pin with embedded weak pull-up resistor Unless otherwise specified by a note, all I/Os are set as floating inputs during and after reset. Alternate functions Functions selected through GPIOx_AFR registers Additional functions Functions directly selected/enabled through peripheral registers DocID025832 Rev 5 31/117 38 Pinouts and pin descriptions STM32F042x4 STM32F042x6 Table 13. STM32F042x pin definitions UFQFPN32 UFQFPN28 TSSPOP20 1 - - - - - VBAT Pin type Notes LQFP32 Pin name (function upon reset) I/O structure WLCSP36 Pin functions LQFP48/UFQFPN48 Pin numbers S - - - - OSC32_IN (2) - OSC32_OUT FTf - CRS_ SYNC I2C1_SDA OSC_IN I/O FTf - I2C1_SCL OSC_OUT NRST I/O RST - Device reset input / internal reset output (active low) 15 VSSA S (3) Analog ground 5 VDDA S - Analog power supply A6 - - - - PC13 I/O TC 3 B6 - - - - PC14OSC32_IN (PC14) I/O TC 4 C6 - - - - PC15OSC32_OUT (PC15) I/O TC 5 B5 2 2 2 2 PF0-OSC_IN (PF0) I/O 6 C5 3 3 3 3 PF1-OSC_OUT (PF1) 7 D5 4 4 4 4 8 D6 32 0 16 9 E5 5 5 5 F6 6 6 6 Backup power supply WKUP2, RTC_TAMP1, RTC_TS, RTC_OUT 2 10 Additional functions Alternate function 6 PA0 I/O TTa (1) (2) (1) (2) (1) - USART2_CTS, TIM2_CH1_ETR, TSC_G1_IO1 RTC_ TAMP2, WKUP1, ADC_IN0, ADC_IN1 11 D4 7 7 7 7 PA1 I/O TTa - USART2_RTS, TIM2_CH2, TSC_G1_IO2, EVENTOUT 12 E4 8 8 8 8 PA2 I/O TTa - USART2_TX, TIM2_CH3, TSC_G1_IO3 ADC_IN2, WKUP4 13 F5 9 9 9 9 PA3 I/O TTa - USART2_RX, TIM2_CH4, TSC_G1_IO4 ADC_IN3 32/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Pinouts and pin descriptions Table 13. STM32F042x pin definitions (continued) 14 15 16 17 C3 D3 E3 F4 10 11 12 13 10 11 12 13 10 11 12 13 10 11 12 13 PA4 Pin type I/O PA5 I/O PA6 I/O PA7 I/O TTa TTa TTa TTa Notes Pin name (function upon reset) I/O structure TSSPOP20 Pin functions UFQFPN28 UFQFPN32 LQFP32 WLCSP36 LQFP48/UFQFPN48 Pin numbers Alternate function Additional functions - SPI1_NSS, I2S1_WS, TIM14_CH1, TSC_G2_IO1, USART2_CK USB_NOE ADC_IN4 - SPI1_SCK, I2S1_CK, CEC, TIM2_CH1_ETR, TSC_G2_IO2 ADC_IN5 - SPI1_MISO, I2S1_MCK, TIM3_CH1, TIM1_BKIN, TIM16_CH1, TSC_G2_IO3, EVENTOUT ADC_IN6 - SPI1_MOSI, I2S1_SD, TIM3_CH2, TIM14_CH1, TIM1_CH1N, TIM17_CH1, TSC_G2_IO4, EVENTOUT ADC_IN7 ADC_IN8 18 F3 14 14 14 - PB0 I/O TTa - TIM3_CH3, TIM1_CH2N, TSC_G3_IO2, EVENTOUT 19 F2 15 15 15 14 PB1 I/O TTa - TIM3_CH4, TIM14_CH1, TIM1_CH3N, TSC_G3_IO3 ADC_IN9 20 D2 - 16 - - PB2 I/O FT - TSC_G3_IO4 - 21 - - - - - PB10 I/O FTf - SPI2_SCK, CEC, TSC_SYNC, TIM2_CH3, I2C1_SCL - 22 - - - - - PB11 I/O FTf - TIM2_CH4, EVENTOUT, I2C1_SDA - 23 F1 16 0 16 15 VSS S - - Ground 24 - - - 17 16 VDD S - - Digital power supply 25 - - - - - PB12 I/O FT - DocID025832 Rev 5 TIM1_BKIN, SPI2_NSS, EVENTOUT - 33/117 38 Pinouts and pin descriptions STM32F042x4 STM32F042x6 Table 13. STM32F042x pin definitions (continued) WLCSP36 LQFP32 UFQFPN32 UFQFPN28 TSSPOP20 Pin name (function upon reset) I/O structure Notes Pin functions LQFP48/UFQFPN48 Pin numbers 26 - - - - - PB13 I/O FTf - SPI2_SCK, TIM1_CH1N, I2C1_SCL - 27 - - - - - PB14 I/O FTf - SPI2_MISO, TIM1_CH2N, I2C1_SDA - 28 - - - - - PB15 I/O FT - SPI2_MOSI, TIM1_CH3N WKUP7, RTC_REFIN FT (4) USART1_CK, TIM1_CH1, EVENTOUT, MCO, CRS_SYNC - FTf (4) USART1_TX, TIM1_CH2, TSC_G4_IO1, I2C1_SCL - (4) USART1_RX, TIM1_CH3, TIM17_BKIN, TSC_G4_IO2, I2C1_SDA - (4) CAN_RX, USART1_CTS, TIM1_CH4, TSC_G4_IO3, EVENTOUT, I2C1_SCL USB_DM (4) CAN_TX,USART1_RTS, TIM1_ETR, TSC_G4_IO4, EVENTOUT, I2C1_SDA USB_DP IR_OUT, SWDIO USB_NOE - 29 30 31 32 E2 D1 C1 C2 18 19 20 21 18 19 20 21 - 19 20 17 18 19(5) 17(5) 20(5) 18(5) PA8 I/O PA9 I/O PA10 PA11 I/O I/O FTf FTf Alternate function Additional functions PA12 I/O FTf 19 PA13 I/O FT - - VSS S - - Ground 17 18 16 VDDIO2 S - - Digital power supply 24 22 20 PA14 I/O FT 33 A1 22 22 34 B1 23 23 21 35 - - - 36 E1 17 37 B2 24 34/117 - Pin type DocID025832 Rev 5 (4) (6) (4) (6) USART2_TX, SWCLK - STM32F042x4 STM32F042x6 Pinouts and pin descriptions Table 13. STM32F042x pin definitions (continued) 38 39 40 41 42 A2 B3 A3 E6 C4 25 26 27 28 29 25 26 27 28 29 23 24 25 26 27 - - - - - PA15 PB3 Pin type I/O I/O PB4 I/O PB5 I/O PB6 I/O FT FT FT FT FTf Notes Pin name (function upon reset) I/O structure TSSPOP20 Pin functions UFQFPN28 UFQFPN32 LQFP32 WLCSP36 LQFP48/UFQFPN48 Pin numbers Alternate function Additional functions (4) SPI1_NSS, I2S1_WS, USART2_RX, TIM2_CH1_ETR, EVENTOUT, USB_NOE - - SPI1_SCK, I2S1_CK, TIM2_CH2, TSC_G5_IO1, EVENTOUT - - SPI1_MISO, I2S1_MCK, TIM17_BKIN, TIM3_CH1, TSC_G5_IO2, EVENTOUT - - SPI1_MOSI, I2S1_SD, I2C1_SMBA, TIM16_BKIN, TIM3_CH2 WKUP6 - I2C1_SCL, USART1_TX, TIM16_CH1N, TSC_G5_I03 - - 43 A4 30 30 28 - PB7 I/O FTf - I2C1_SDA, USART1_RX, TIM17_CH1N, TSC_G5_IO4 44 - - 31 - - PF11-BOOT0 I/O FT - - Boot memory selection - I2C1_SCL, CEC, TIM16_CH1, TSC_SYNC, CAN_RX Boot memory selection - I2C1_SCL, CEC, TIM16_CH1, TSC_SYNC, CAN_RX - - 45 B4 - 31 - - 32 1 - 1 - PB8-BOOT0 PB8 I/O I/O FTf FTf DocID025832 Rev 5 35/117 38 Pinouts and pin descriptions STM32F042x4 STM32F042x6 Table 13. STM32F042x pin definitions (continued) Pin type Notes Pin name (function upon reset) I/O structure TSSPOP20 Pin functions UFQFPN28 UFQFPN32 LQFP32 WLCSP36 LQFP48/UFQFPN48 Pin numbers Alternate function Additional functions SPI2_NSS, I2C1_SDA, IR_OUT, TIM17_CH1, EVENTOUT, CAN_TX - 46 - - - - - PB9 I/O FTf - 47 - 32 0 - - VSS S - - Ground 48 A5 1 1 - - VDD S - - Digital power supply 1. PC13, PC14 and PC15 are supplied through the power switch. Since the switch only sinks a limited amount of current (3 mA), the use of GPIOs PC13 to PC15 in output mode is limited: - The speed should not exceed 2 MHz with a maximum load of 30 pF. - These GPIOs must not be used as current sources (e.g. to drive an LED). 2. After the first RTC domain power-up, PC13, PC14 and PC15 operate as GPIOs. Their function then depends on the content of the RTC registers which are not reset by the system reset. For details on how to manage these GPIOs, refer to the RTC domain and RTC register descriptions in the reference manual. 3. Distinct VSSA pin is only available on 48-pin packages. On all other packages, the pin number corresponds to the VSS pin to which VSSA pad of the silicon die is connected. 4. PA8, PA9, PA10, PA11, PA12, PA13, PA14 and PA15 I/Os are supplied by VDDIO2. 5. Pin pair PA11/12 can be remapped in place of pin pair PA9/10 using SYSCFG_CFGR1 register. 6. After reset, these pins are configured as SWDIO and SWCLK alternate functions, and the internal pull-up on the SWDIO pin and the internal pull-down on the SWCLK pin are activated. 36/117 DocID025832 Rev 5 DocID025832 Rev 5 Pin name AF0 AF1 AF2 AF3 AF4 AF5 AF6 AF7 PA0 - USART2_CTS TIM2_CH1_ETR TSC_G1_IO1 - - - - PA1 EVENTOUT USART2_RTS TIM2_CH2 TSC_G1_IO2 - - - - PA2 - USART2_TX TIM2_CH3 TSC_G1_IO3 - - - - PA3 - USART2_RX TIM2_CH4 TSC_G1_IO4 - - - - PA4 SPI1_NSS, I2S1_WS USART2_CK USB_NOE TSC_G2_IO1 TIM14_CH1 - - - PA5 SPI1_SCK, I2S1_CK CEC TIM2_CH1_ETR TSC_G2_IO2 - - - - PA6 SPI1_MISO, I2S1_MCK TIM3_CH1 TIM1_BKIN TSC_G2_IO3 - TIM16_CH1 EVENTOUT - PA7 SPI1_MOSI, I2S1_SD TIM3_CH2 TIM1_CH1N TSC_G2_IO4 TIM14_CH1 TIM17_CH1 EVENTOUT - PA8 MCO USART1_CK TIM1_CH1 EVENTOUT CRS_SYNC - - - PA9 - USART1_TX TIM1_CH2 TSC_G4_IO1 I2C1_SCL MCO - - PA10 TIM17_BKIN USART1_RX TIM1_CH3 TSC_G4_IO2 I2C1_SDA - - - PA11 EVENTOUT USART1_CTS TIM1_CH4 TSC_G4_IO3 CAN_RX I2C1_SCL - - PA12 EVENTOUT USART1_RTS TIM1_ETR TSC_G4_IO4 CAN_TX I2C1_SDA - - PA13 SWDIO IR_OUT USB_NOE - - - - - PA14 SWCLK USART2_TX - - - - - - PA15 SPI1_NSS, I2S1_WS USART2_RX TIM2_CH1_ETR EVENTOUT - USB_NOE - - STM32F042x4 STM32F042x6 Table 14. Alternate functions selected through GPIOA_AFR registers for port A Pinouts and pin descriptions 37/117 DocID025832 Rev 5 Pin name AF0 AF1 AF2 AF3 AF4 AF5 PB0 EVENTOUT TIM3_CH3 TIM1_CH2N TSC_G3_IO2 - - PB1 TIM14_CH1 TIM3_CH4 TIM1_CH3N TSC_G3_IO3 - - PB2 - - - TSC_G3_IO4 - - PB3 SPI1_SCK, I2S1_CK EVENTOUT TIM2_CH2 TSC_G5_IO1 - - PB4 SPI1_MISO, I2S1_MCK TIM3_CH1 EVENTOUT TSC_G5_IO2 - TIM17_BKIN PB5 SPI1_MOSI, I2S1_SD TIM3_CH2 TIM16_BKIN I2C1_SMBA - - PB6 USART1_TX I2C1_SCL TIM16_CH1N TSC_G5_IO3 - - PB7 USART1_RX I2C1_SDA TIM17_CH1N TSC_G5_IO4 - - PB8 CEC I2C1_SCL TIM16_CH1 TSC_SYNC CAN_RX - PB9 IR_OUT I2C1_SDA TIM17_CH1 EVENTOUT CAN_TX SPI2_NSS PB10 CEC I2C1_SCL TIM2_CH3 TSC_SYNC - SPI2_SCK PB11 EVENTOUT I2C1_SDA TIM2_CH4 - - - PB12 SPI2_NSS EVENTOUT TIM1_BKIN - - - PB13 SPI2_SCK - TIM1_CH1N - - I2C1_SCL PB14 SPI2_MISO - TIM1_CH2N - - I2C1_SDA PB15 SPI2_MOSI - TIM1_CH3N - - - Pin name AF0 AF1 PF0 CRS_SYNC I2C1_SDA PF1 - I2C1_SCL STM32F042x4 STM32F042x6 Table 16. Alternate functions selected through GPIOF_AFR registers for port F Pinouts and pin descriptions 38/117 Table 15. Alternate functions selected through GPIOB_AFR registers for port B STM32F042x4 STM32F042x6 5 Memory mapping Memory mapping To the difference of STM32F042x6 memory map in Figure 10, the two bottom code memory spaces of STM32F042x4 end at 0x0000 3FFF and 0x0800 3FFF, respectively. Figure 10. STM32F042x6 memory map [)))))))) [)) 5HVHUYHG $+% [( [( [ &RUWH[0LQWHUQDO SHULSKHUDOV 5HVHUYHG 5HVHUYHG [& [)) $+% 5HVHUYHG [ 5HVHUYHG [$ [ 5HVHUYHG [))))))) [))))& [)))) [ $3% 5HVHUYHG 2SWLRQ%\WHV [ 5HVHUYHG 6\VWHPPHPRU\ 5HVHUYHG [ [)))& $3% [ [ [ 5HVHUYHG 5HVHUYHG 3HULSKHUDOV [ 5HVHUYHG )ODVKPHPRU\ [ 65$0 [ 5HVHUYHG &2'( [ )ODVKV\VWHP PHPRU\RU65$0 GHSHQGLQJRQ%227 FRQILJXUDWLRQ [ [ 06Y9 DocID025832 Rev 5 39/117 41 Memory mapping STM32F042x4 STM32F042x6 Table 17. STM32F042x4/x6 peripheral register boundary addresses Bus AHB2 AHB1 APB 40/117 Boundary address Size Peripheral 0x4800 1800 - 0x5FFF FFFF ~384 MB Reserved 0x4800 1400 - 0x4800 17FF 1 KB GPIOF 0x4800 0C00 - 0x4800 13FF 2 KB Reserved 0x4800 0800 - 0x4800 0BFF 1 KB GPIOC 0x4800 0400 - 0x4800 07FF 1 KB GPIOB 0x4800 0000 - 0x4800 03FF 1 KB GPIOA 0x4002 4400 - 0x47FF FFFF ~128 MB Reserved 0x4002 4000 - 0x4002 43FF 1 KB TSC 0x4002 3400 - 0x4002 3FFF 3 KB Reserved 0x4002 3000 - 0x4002 33FF 1 KB CRC 0x4002 2400 - 0x4002 2FFF 3 KB Reserved 0x4002 2000 - 0x4002 23FF 1 KB Flash memory interface 0x4002 1400 - 0x4002 1FFF 3 KB Reserved 0x4002 1000 - 0x4002 13FF 1 KB RCC 0x4002 0400 - 0x4002 0FFF 3 KB Reserved 0x4002 0000 - 0x4002 03FF 1 KB DMA 0x4001 8000 - 0x4001 FFFF 32 KB Reserved 0x4001 5C00 - 0x4001 7FFF 9 KB Reserved 0x4001 5800 - 0x4001 5BFF 1 KB DBGMCU 0x4001 4C00 - 0x4001 57FF 3 KB Reserved 0x4001 4800 - 0x4001 4BFF 1 KB TIM17 0x4001 4400 - 0x4001 47FF 1 KB TIM16 0x4001 3C00 - 0x4001 43FF 2 KB Reserved 0x4001 3800 - 0x4001 3BFF 1 KB USART1 0x4001 3400 - 0x4001 37FF 1 KB Reserved 0x4001 3000 - 0x4001 33FF 1 KB SPI1/I2S1 0x4001 2C00 - 0x4001 2FFF 1 KB TIM1 0x4001 2800 - 0x4001 2BFF 1 KB Reserved 0x4001 2400 - 0x4001 27FF 1 KB ADC 0x4001 0800 - 0x4001 23FF 7 KB Reserved 0x4001 0400 - 0x4001 07FF 1 KB EXTI 0x4001 0000 - 0x4001 03FF 1 KB SYSCFG 0x4000 8000 - 0x4000 FFFF 32 KB Reserved DocID025832 Rev 5 STM32F042x4 STM32F042x6 Memory mapping Table 17. STM32F042x4/x6 peripheral register boundary addresses (continued) Bus APB Boundary address Size Peripheral 0x4000 7C00 - 0x4000 7FFF 1 KB Reserved 0x4000 7800 - 0x4000 7BFF 1 KB CEC 0x4000 7400 - 0x4000 77FF 1 KB Reserved 0x4000 7000 - 0x4000 73FF 1 KB PWR 0x4000 6C00 - 0x4000 6FFF 1 KB CRS 0x4000 6800 - 0x4000 6BFF0 1 KB Reserved 0x4000 6400 - 0x4000 67FF 1 KB BxCAN 0x4000 6000 - 0x4000 63FF 1 KB USB/CAN RAM 0x4000 5C00 - 0x4000 5FFF 1 KB USB 0x4000 5800 - 0x4000 5BFF 1 KB Reserved 0x4000 5400 - 0x4000 57FF 1 KB I2C1 0x4000 4800 - 0x4000 53FF 3 KB Reserved 0x4000 4400 - 0x4000 47FF 1 KB USART2 0x4000 3C00 - 0x4000 43FF 2 KB Reserved 0x4000 3800 - 0x4000 3BFF 1 KB SPI2 0x4000 3400 - 0x4000 37FF 1 KB Reserved 0x4000 3000 - 0x4000 33FF 1 KB IWDG 0x4000 2C00 - 0x4000 2FFF 1 KB WWDG 0x4000 2800 - 0x4000 2BFF 1 KB RTC 0x4000 2400 - 0x4000 27FF 1 KB Reserved 0x4000 2000 - 0x4000 23FF 1 KB TIM14 0x4000 0800 - 0x4000 1FFF 6 KB Reserved 0x4000 0400 - 0x4000 07FF 1 KB TIM3 0x4000 0000 - 0x4000 03FF 1 KB TIM2 DocID025832 Rev 5 41/117 41 Electrical characteristics STM32F042x4 STM32F042x6 6 Electrical characteristics 6.1 Parameter conditions Unless otherwise specified, all voltages are referenced to VSS. 6.1.1 Minimum and maximum values Unless otherwise specified, the minimum and maximum values are guaranteed in the worst conditions of ambient temperature, supply voltage and frequencies by tests in production on 100% of the devices with an ambient temperature at TA = 25 C and TA = TAmax (given by the selected temperature range). Data based on characterization results, design simulation and/or technology characteristics are indicated in the table footnotes and are not tested in production. Based on characterization, the minimum and maximum values refer to sample tests and represent the mean value plus or minus three times the standard deviation (mean 3). 6.1.2 Typical values Unless otherwise specified, typical data are based on TA = 25 C, VDD = VDDA = 3.3 V. They are given only as design guidelines and are not tested. Typical ADC accuracy values are determined by characterization of a batch of samples from a standard diffusion lot over the full temperature range, where 95% of the devices have an error less than or equal to the value indicated (mean 2). 6.1.3 Typical curves Unless otherwise specified, all typical curves are given only as design guidelines and are not tested. 6.1.4 Loading capacitor The loading conditions used for pin parameter measurement are shown in Figure 11. 6.1.5 Pin input voltage The input voltage measurement on a pin of the device is described in Figure 12. Figure 11. Pin loading conditions Figure 12. Pin input voltage 0&8SLQ 0&8SLQ & S) 9,1 069 42/117 DocID025832 Rev 5 069 STM32F042x4 STM32F042x6 6.1.6 Electrical characteristics Power supply scheme Figure 13. Power supply scheme 9%$7 %DFNXSFLUFXLWU\ /6(57& %DFNXSUHJLVWHUV 9 3RZHUVZLWFK 9'' 9&25( [9'' 5HJXODWRU [Q) *3,2V ,1 [) /HYHOVKLIWHU 287 ,2 ORJLF /HYHOVKLIWHU 9'',2 ,2 ORJLF .HUQHOORJLF &38'LJLWDO 0HPRULHV [966 9'',2 9'',2 9'',2 Q) ) 287 *3,2V ,1 966 9''$ 9''$ Q) ) 95() 95() $'& $QDORJ 5&V3// 966$ 06Y9 Caution: Each power supply pair (VDD/VSS, VDDA/VSSA etc.) must be decoupled with filtering ceramic capacitors as shown above. These capacitors must be placed as close as possible to, or below, the appropriate pins on the underside of the PCB to ensure the good functionality of the device. DocID025832 Rev 5 43/117 89 Electrical characteristics 6.1.7 STM32F042x4 STM32F042x6 Current consumption measurement Figure 14. Current consumption measurement scheme , ''B9%$7 9 %$7 , '' 9 '' 9 '',2 , ''$ 9 ''$ 069 44/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 6.2 Electrical characteristics Absolute maximum ratings Stresses above the absolute maximum ratings listed in Table 18: Voltage characteristics, Table 19: Current characteristics and Table 20: Thermal characteristics may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these conditions is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. Table 18. Voltage characteristics(1) Symbol VDD-VSS Ratings External main supply voltage VDDIO2-VSS External I/O supply voltage VDDA-VSS External analog supply voltage VDD-VDDA Allowed voltage difference for VDD > VDDA VBAT-VSS External backup supply voltage VIN(2) |VDDx| |VSSx - VSS| VESD(HBM) Min Max Unit - 0.3 4.0 V - 0.3 4.0 V - 0.3 4.0 V - 0.4 V - 0.3 4.0 Input voltage on FT and FTf pins VSS - 0.3 Input voltage on TTa pins VSS - 0.3 4.0 V Input voltage on any other pin VSS - 0.3 4.0 V Variations between different VDD power pins - 50 mV Variations between all the different ground pins - 50 mV Electrostatic discharge voltage (human body model) VDDIOx + 4.0 V (3) V see Section 6.3.12: Electrical sensitivity characteristics - 1. All main power (VDD, VDDA) and ground (VSS, VSSA) pins must always be connected to the external power supply, in the permitted range. 2. VIN maximum must always be respected. Refer to Table 19: Current characteristics for the maximum allowed injected current values. 3. Valid only if the internal pull-up/pull-down resistors are disabled. If internal pull-up or pull-down resistor is enabled, the maximum limit is 4 V. DocID025832 Rev 5 45/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Table 19. Current characteristics Symbol Ratings Max. IVDD Total current into sum of all VDD power lines (source)(1) 120 IVSS (1) -120 Total current out of sum of all VSS ground lines (sink) IVDD(PIN) Maximum current into each VDD power pin (source) (1) 100 IVSS(PIN) Maximum current out of each VSS ground pin (sink)(1) -100 IIO(PIN) Output current sunk by any I/O and control pin 25 Output current source by any I/O and control pin Total output current sunk by sum of all I/Os and control pins IIO(PIN) IINJ(PIN)(3) -25 (2) 80 Total output current sourced by sum of all I/Os and control pins(2) -80 Total output current sourced by sum of all I/Os supplied by VDDIO2 -40 Injected current on FT and FTf pins -5/+0(4) Injected current on TC and RST pin 5 Injected current on TTa pins(5) IINJ(PIN) Total injected current (sum of all I/O and control Unit mA 5 pins)(6) 25 1. All main power (VDD, VDDA) and ground (VSS, VSSA) pins must always be connected to the external power supply, in the permitted range. 2. This current consumption must be correctly distributed over all I/Os and control pins. The total output current must not be sunk/sourced between two consecutive power supply pins referring to high pin count QFP packages. 3. A positive injection is induced by VIN > VDDIOx while a negative injection is induced by VIN < VSS. IINJ(PIN) must never be exceeded. Refer to Table 18: Voltage characteristics for the maximum allowed input voltage values. 4. Positive injection is not possible on these I/Os and does not occur for input voltages lower than the specified maximum value. 5. On these I/Os, a positive injection is induced by VIN > VDDA. Negative injection disturbs the analog performance of the device. See note (2) below Table 56: ADC accuracy. 6. When several inputs are submitted to a current injection, the maximum IINJ(PIN) is the absolute sum of the positive and negative injected currents (instantaneous values). Table 20. Thermal characteristics Symbol TSTG TJ 46/117 Ratings Storage temperature range Maximum junction temperature DocID025832 Rev 5 Value Unit -65 to +150 C 150 C STM32F042x4 STM32F042x6 Electrical characteristics 6.3 Operating conditions 6.3.1 General operating conditions Table 21. General operating conditions Symbol Parameter Conditions Min Max Unit fHCLK Internal AHB clock frequency - 0 48 fPCLK Internal APB clock frequency - 0 48 VDD Standard operating voltage - 2.0 3.6 V Must not be supplied if VDD is not present 1.65 3.6 V VDD 3.6 2.4 3.6 1.65 3.6 TC and RST I/O -0.3 VDDIOx+0.3 TTa I/O -0.3 VDDA+0.3(1) -0.3 5.5(1) LQFP48 - 364 UFQFPN48 - 606 WLCSP36 - 313 LQFP32 - 351 UFQFPN32 - 526 UFQFPN28 - 170 TSSOP20 - 263 -40 85 -40 105 VDDIO2 VDDA VBAT VIN I/O supply voltage Analog operating voltage (ADC not used) Must have a potential equal to or higher than VDD Analog operating voltage (ADC used) Backup operating voltage - I/O input voltage FT and FTf I/O PD Power dissipation at TA = 85 C for suffix 6 or TA = 105 C for suffix 7(2) Maximum power dissipation Ambient temperature for the suffix 7 version Maximum power dissipation -40 105 Low power dissipation(3) -40 125 Suffix 6 version -40 105 Suffix 7 version -40 125 TA TJ V Ambient temperature for the suffix 6 version Junction temperature range Low power dissipation (3) MHz V V mW C C C 1. For operation with a voltage higher than VDDIOx + 0.3 V, the internal pull-up resistor must be disabled. 2. If TA is lower, higher PD values are allowed as long as TJ does not exceed TJmax. See Section 7.8: Thermal characteristics. 3. In low power dissipation state, TA can be extended to this range as long as TJ does not exceed TJmax (see Section 7.8: Thermal characteristicsSection 7.8: Thermal characteristics). 6.3.2 Operating conditions at power-up / power-down The parameters given in Table 22 are derived from tests performed under the ambient temperature condition summarized in Table 21. DocID025832 Rev 5 47/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Table 22. Operating conditions at power-up / power-down Symbol Parameter VDD rise time rate tVDD - VDD fall time rate VDDA rise time rate tVDDA 6.3.3 Conditions - VDDA fall time rate Min Max 0 20 0 20 Unit s/V Embedded reset and power control block characteristics The parameters given in Table 23 are derived from tests performed under the ambient temperature and supply voltage conditions summarized in Table 21: General operating conditions. Table 23. Embedded reset and power control block characteristics Symbol VPOR/PDR(1) VPDRhyst tRSTTEMPO(4) Parameter Conditions Min Typ Max Unit Power on/power down reset threshold Falling edge(2) 1.80 1.88 1.96(3) V 1.84(3) 1.92 2.00 V PDR hysteresis - - 40 - mV Reset temporization - 1.50 2.50 4.50 ms Rising edge 1. The PDR detector monitors VDD and also VDDA (if kept enabled in the option bytes). The POR detector monitors only VDD. 2. The product behavior is guaranteed by design down to the minimum VPOR/PDR value. 3. Data based on characterization results, not tested in production. 4. Guaranteed by design, not tested in production. Table 24. Programmable voltage detector characteristics Symbol 48/117 Parameter VPVD0 PVD threshold 0 VPVD1 PVD threshold 1 VPVD2 PVD threshold 2 VPVD3 PVD threshold 3 VPVD4 PVD threshold 4 VPVD5 PVD threshold 5 Conditions Min Typ Max Unit Rising edge 2.1 2.18 2.26 V Falling edge 2 2.08 2.16 V Rising edge 2.19 2.28 2.37 V Falling edge 2.09 2.18 2.27 V Rising edge 2.28 2.38 2.48 V Falling edge 2.18 2.28 2.38 V Rising edge 2.38 2.48 2.58 V Falling edge 2.28 2.38 2.48 V Rising edge 2.47 2.58 2.69 V Falling edge 2.37 2.48 2.59 V Rising edge 2.57 2.68 2.79 V Falling edge 2.47 2.58 2.69 V DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Table 24. Programmable voltage detector characteristics (continued) Symbol Parameter Conditions Min Typ Max Unit Rising edge 2.66 2.78 2.9 V Falling edge 2.56 2.68 2.8 V Rising edge 2.76 2.88 3 V Falling edge 2.66 2.78 2.9 V VPVD6 PVD threshold 6 VPVD7 PVD threshold 7 VPVDhyst(1) PVD hysteresis - - 100 - mV PVD current consumption - - 0.15 0.26(1) A IDD(PVD) 1. Guaranteed by design, not tested in production. 6.3.4 Embedded reference voltage The parameters given in Table 25 are derived from tests performed under the ambient temperature and supply voltage conditions summarized in Table 21: General operating conditions. Table 25. Embedded internal reference voltage Symbol VREFINT Parameter Conditions Internal reference voltage -40 C < TA < +105 C Min Typ Max Unit 1.2 1.23 1.25 V tSTART ADC_IN17 buffer startup time - - - 10(1) s tS_vrefint ADC sampling time when reading the internal reference voltage - 4(1) - - s VREFINT Internal reference voltage spread over the temperature range VDDA = 3 V - - 10(1) mV - - 100(1) - 100(1) ppm/C TCoeff Temperature coefficient 1. Guaranteed by design, not tested in production. 6.3.5 Supply current characteristics The current consumption is a function of several parameters and factors such as the operating voltage, ambient temperature, I/O pin loading, device software configuration, operating frequencies, I/O pin switching rate, program location in memory and executed binary code. The current consumption is measured as described in Figure 14: Current consumption measurement scheme. All Run-mode current consumption measurements given in this section are performed with a reduced code that gives a consumption equivalent to CoreMark code. DocID025832 Rev 5 49/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Typical and maximum current consumption The MCU is placed under the following conditions: * All I/O pins are in analog input mode * All peripherals are disabled except when explicitly mentioned * * The Flash memory access time is adjusted to the fHCLK frequency: - 0 wait state and Prefetch OFF from 0 to 24 MHz - 1 wait state and Prefetch ON above 24 MHz When the peripherals are enabled fPCLK = fHCLK The parameters given in Table 26 to Table 28 are derived from tests performed under ambient temperature and supply voltage conditions summarized in Table 21: General operating conditions. Parameter Symbol Table 26. Typical and maximum current consumption from VDD supply at VDD = 3.6 V All peripherals enabled(1) Conditions 50/117 Supply current in Run mode, code executing from Flash memory IDD Max @ TA(2) fHCLK Max @ TA(2) HSE bypass, PLL on HSE bypass, PLL off HSI clock, PLL on HSI clock, PLL off Unit Typ Typ HSI48 All peripherals disabled 25 C 85 C 105 C 25 C 85 C 105 C 48 MHz 20.3 23.2 23.4 24.6 12.7 14.4 14.4 14.7 48 MHz 20.2 22.9 23.0 23.9 12.6 14.1 14.3 14.4 32 MHz 14.0 16.0 16.1 16.7 8.7 9.5 9.7 10.3 24 MHz 11.0 13.5 13.7 13.8 6.9 7.6 7.8 8.2 8 MHz 3.9 5.2 5.3 5.6 2.6 3.1 3.2 3.3 1 MHz 0.9 1.3 1.5 1.8 0.7 1.0 1.1 1.3 48 MHz 20.5 23.1 23.3 23.6 12.8 14.6 14.6 15.0 32 MHz 14.3 15.6 15.9 17.0 8.6 9.5 9.7 10.0 24 MHz 11.2 13.6 13.8 14.8 6.9 7.4 7.5 7.7 8 MHz 4.1 5.2 5.3 5.6 2.6 3.1 3.1 3.3 DocID025832 Rev 5 mA STM32F042x4 STM32F042x6 Electrical characteristics Parameter Symbol Table 26. Typical and maximum current consumption from VDD supply at VDD = 3.6 V (continued) All peripherals enabled(1) Conditions Supply current in Run mode, code executing from RAM Supply current in Sleep mode IDD Max @ TA(2) fHCLK Max @ TA(2) 48 MHz 19.3 Unit Typ Typ HSI48 All peripherals disabled 25 C 85 C 105 C 21.9 22.1 23.7 22.0 22.1(3) 85 C 105 C 11.9 13.4 13.6 13.7 11.7 13.3(3) 13.5 13.7(3) 48 MHz 19.2 32 MHz 13.4 15.8 15.9 16.0 7.9 8.8 8.9 9.7 24 MHz 10.3 12.6 13.0 13.4 6.2 8.0 8.2 8.3 8 MHz 3.6 4.1 4.3 4.4 2.0 2.1 2.1 2.5 1 MHz 0.8 0.9 0.9 1.1 0.4 0.5 0.6 0.8 48 MHz 19.5 22.0 22.1 22.5 11.8 13.6 13.8 13.9 32 MHz 13.5 16.3 16.4 16.6 8.0 8.8 9.1 9.9 24 MHz 10.5 12.8 13.0 13.8 6.5 8.0 8.1 8.4 HSI clock, PLL off 8 MHz 3.7 4.7 5.0 5.3 2.1 2.3 2.4 3.0 HSI48 48 MHz 12.4 15.1 16.3 16.7 3.0 3.2 3.3 3.4 48 MHz 12.3 15.0(3) 16.0 16.2(3) 2.9 3.2(3) 3.3 3.4(3) 32 MHz 8.5 10.6 11.2 11.7 1.9 2.1 2.2 2.5 24 MHz 6.5 8.1 8.5 8.7 1.6 1.8 1.8 1.9 8 MHz 2.3 3.0 3.1 3.2 0.7 0.8 0.8 0.9 1 MHz 0.4 0.4 0.4 0.6 0.1 0.3 0.3 0.4 48 MHz 12.4 15.3 15.7 15.9 3.0 3.0 3.2 3.4 32 MHz 8.6 10.7 11.3 11.6 2.1 2.2 2.2 2.5 24 MHz 6.6 8.4 8.7 8.9 1.6 1.6 1.7 1.9 8 MHz 2.4 3.2 3.4 3.6 0.6 0.8 0.9 1.0 HSE bypass, PLL on HSE bypass, PLL off HSI clock, PLL on HSE bypass, PLL on HSE bypass, PLL off HSI clock, PLL on HSI clock, PLL off 21.8 (3) 25 C mA 1. USB is kept disabled as this IP functions only with a 48 MHz clock. 2. Data based on characterization results, not tested in production unless otherwise specified. 3. Data based on characterization results and tested in production (using one common test limit for sum of IDD and IDDA). DocID025832 Rev 5 51/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Table 27. Typical and maximum current consumption from the VDDA supply VDDA = 2.4 V Symbol Parameter Conditions (1) IDDA Max @ TA(2) fHCLK Max @ TA(2) HSE bypass, PLL on HSE bypass, PLL off HSI clock, PLL on HSI clock, PLL off 48 MHz 309 Unit Typ Typ HSI48 Supply current in Run or Sleep mode, code executing from Flash memory or RAM VDDA = 3.6 V 25 C 85 C 105 C 325 332 342 167 (3) 176 179 (3) 25 C 85 C 105 C 317 161 334 (3) 181 338 344 193 197(3) 48 MHz 148 32 MHz 102 119 124 126 111 128 135 137 24 MHz 80 95 99 100 88 102 106 108 8 MHz 2.7 3.7 4.2 4.5 3.5 4.7 5.2 5.5 1 MHz 2.7 3.7 4.2 4.2 3.6 4.7 5.2 5.5 48 MHz 220 242 251 254 242 264 275 279 32 MHz 173 193 200 202 191 211 219 221 24 MHz 151 169 175 177 167 184 191 193 8 MHz 72 82 85 85 82 92 95 95 A 1. Current consumption from the VDDA supply is independent of whether the digital peripherals are enabled or disabled, being in Run or Sleep mode or executing from Flash memory or RAM. Furthermore, when the PLL is off, IDDA is independent from the frequency. 2. Data based on characterization results, not tested in production unless otherwise specified. 3. Data based on characterization results and tested in production (using one common test limit for sum of IDD and IDDA). 52/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics 2.0 V 2.4 V 2.7 V 3.0 V 3.3 V 3.6 V TA = TA = TA = 25C 85C 105C 14.3 14.5 14.6 14.7 14.8 14.9 21.0 47.0 64.0 2.9 3.1 3.2 3.3 3.4 3.5 6.5 32.0 44.0 LSI ON and IWDG ON 0.8 0.9 1.1 1.2 1.3 1.5 - - - LSI OFF and IWDG OFF 0.6 0.7 0.8 0.9 1.0 1.1 2.0 2.5 3.0 Regulator in run mode, all oscillators OFF 2.0 2.1 2.2 2.4 2.5 2.7 3.5 3.5 4.5 Regulator in low-power mode, all oscillators OFF 2.0 2.1 2.2 2.4 2.5 2.7 3.5 3.5 4.5 LSI ON and IWDG ON 2.4 2.6 2.8 3.0 3.1 3.4 - - - LSI OFF and IWDG OFF 1.9 2.0 2.1 2.3 2.4 2.5 3.4 3.5 4.5 Regulator in run mode, all oscillators OFF 1.3 1.3 1.3 1.4 1.4 1.5 - - - Regulator in low-power mode, all oscillators OFF 1.3 1.3 1.3 1.4 1.4 1.5 - - - LSI ON and IWDG ON 1.7 1.8 1.8 2.0 2.1 2.2 - - - LSI OFF and IWDG OFF 1.1 1.2 1.2 1.3 1.3 1.4 - - - Supply current in Standby mode Supply current in Stop mode Supply current in Standby mode VDDA monitoring ON Supply current in Stop mode Regulator in lowpower mode, all oscillators OFF Supply current in Stop mode Supply current in Standby mode VDDA monitoring OFF IDDA Unit Conditions Regulator in run mode, all oscillators OFF IDD Max(1) Typ @VDD (VDD = VDDA) Parameter Symbol Table 28. Typical and maximum consumption in Stop and Standby modes A 1. Data based on characterization results, not tested in production unless otherwise specified. DocID025832 Rev 5 53/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Table 29. Typical and maximum current consumption from the VBAT supply Max(1) Typ @ VBAT 2.4 V 2.7 V 3.3 V 3.6 V RTC domain IDD_VBAT supply current Conditions 1.8 V Parameter 1.65 V Symbol TA = 25 C LSE & RTC ON; "Xtal mode": lower driving capability; LSEDRV[1:0] = '00' 0.5 0.5 0.6 0.7 0.9 1.1 1.2 LSE & RTC ON; "Xtal mode" higher driving capability; LSEDRV[1:0] = '11' 0.8 TA = TA = 85 C 105 C 1.5 Unit 2.0 A 0.9 1.1 1.2 1.4 1.5 1.6 2.0 2.6 1. Data based on characterization results, not tested in production. Typical current consumption The MCU is placed under the following conditions: 54/117 * VDD = VDDA = 3.3 V * All I/O pins are in analog input configuration * The Flash memory access time is adjusted to fHCLK frequency: - 0 wait state and Prefetch OFF from 0 to 24 MHz - 1 wait state and Prefetch ON above 24 MHz * When the peripherals are enabled, fPCLK = fHCLK * PLL is used for frequencies greater than 8 MHz * AHB prescaler of 2, 4, 8 and 16 is used for the frequencies 4 MHz, 2 MHz, 1 MHz and 500 kHz respectively DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Table 30. Typical current consumption, code executing from Flash memory, running from HSE 8 MHz crystal Typical consumption in Run mode Symbol Parameter Typical consumption in Sleep mode fHCLK Unit Peripherals Peripherals Peripherals Peripherals enabled disabled enabled disabled IDD IDDA Current consumption from VDD supply Current consumption from VDDA supply 48 MHz 20.7 12.8 12.3 3.4 36 MHz 15.9 9.9 9.5 2.7 32 MHz 14.3 9.0 8.5 2.5 24 MHz 11.0 7.1 6.6 2.1 16 MHz 7.7 5.0 4.7 1.6 8 MHz 4.3 3.0 2.7 1.2 4 MHz 2.6 2.0 1.7 0.9 2 MHz 1.8 1.5 1.2 0.8 1 MHz 1.4 1.2 1.0 0.8 500 kHz 1.2 1.1 0.8 0.7 48 MHz 163.3 36 MHz 124.3 32 MHz 111.9 24 MHz 87.1 16 MHz 62.5 8 MHz 2.5 4 MHz 2.5 2 MHz 2.5 1 MHz 2.5 500 kHz 2.5 mA A I/O system current consumption The current consumption of the I/O system has two components: static and dynamic. I/O static current consumption All the I/Os used as inputs with pull-up generate current consumption when the pin is externally held low. The value of this current consumption can be simply computed by using the pull-up/pull-down resistors values given in Table 50: I/O static characteristics. For the output pins, any external pull-down or external load must also be considered to estimate the current consumption. Additional I/O current consumption is due to I/Os configured as inputs if an intermediate voltage level is externally applied. This current consumption is caused by the input Schmitt DocID025832 Rev 5 55/117 89 Electrical characteristics STM32F042x4 STM32F042x6 trigger circuits used to discriminate the input value. Unless this specific configuration is required by the application, this supply current consumption can be avoided by configuring these I/Os in analog mode. This is notably the case of ADC input pins which should be configured as analog inputs. Caution: Any floating input pin can also settle to an intermediate voltage level or switch inadvertently, as a result of external electromagnetic noise. To avoid current consumption related to floating pins, they must either be configured in analog mode, or forced internally to a definite digital value. This can be done either by using pull-up/down resistors or by configuring the pins in output mode. I/O dynamic current consumption In addition to the internal peripheral current consumption measured previously (see Table 32: Peripheral current consumption), the I/Os used by an application also contribute to the current consumption. When an I/O pin switches, it uses the current from the I/O supply voltage to supply the I/O pin circuitry and to charge/discharge the capacitive load (internal or external) connected to the pin: I SW = V DDIOx x f SW x C where ISW is the current sunk by a switching I/O to charge/discharge the capacitive load VDDIOx is the I/O supply voltage fSW is the I/O switching frequency C is the total capacitance seen by the I/O pin: C = CINT + CEXT + CS CS is the PCB board capacitance including the pad pin. The test pin is configured in push-pull output mode and is toggled by software at a fixed frequency. 56/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Table 31. Switching output I/O current consumption Symbol Parameter Conditions(1) VDDIOx = 3.3 V C =CINT VDDIOx = 3.3 V CEXT = 0 pF C = CINT + CEXT+ CS VDDIOx = 3.3 V CEXT = 10 pF C = CINT + CEXT+ CS ISW I/O current consumption VDDIOx = 3.3 V CEXT = 22 pF C = CINT + CEXT+ CS VDDIOx = 3.3 V CEXT = 33 pF C = CINT + CEXT+ CS VDDIOx = 3.3 V CEXT = 47 pF C = CINT + CEXT+ CS C = Cint VDDIOx = 2.4 V CEXT = 47 pF C = CINT + CEXT+ CS C = Cint I/O toggling frequency (fSW) Typ 4 MHz 0.07 8 MHz 0.15 16 MHz 0.31 24 MHz 0.53 48 MHz 0.92 4 MHz 0.18 8 MHz 0.37 16 MHz 0.76 24 MHz 1.39 48 MHz 2.188 4 MHz 0.32 8 MHz 0.64 16 MHz 1.25 24 MHz 2.23 48 MHz 4.442 4 MHz 0.49 8 MHz 0.94 16 MHz 2.38 24 MHz 3.99 4 MHz 0.64 8 MHz 1.25 16 MHz 3.24 24 MHz 5.02 4 MHz 0.81 8 MHz 1.7 16 MHz 3.67 4 MHz 0.66 8 MHz 1.43 16 MHz 2.45 24 MHz 4.97 Unit mA 1. CS = 7 pF (estimated value). DocID025832 Rev 5 57/117 89 Electrical characteristics STM32F042x4 STM32F042x6 On-chip peripheral current consumption The current consumption of the on-chip peripherals is given in Table 32. The MCU is placed under the following conditions: * All I/O pins are in analog mode * All peripherals are disabled unless otherwise mentioned * The given value is calculated by measuring the current consumption * - with all peripherals clocked off - with only one peripheral clocked on Ambient operating temperature and supply voltage conditions summarized in Table 18: Voltage characteristics Table 32. Peripheral current consumption Peripheral AHB 58/117 Typical consumption at 25 C BusMatrix(1) 2.2 CRC 1.9 DMA 5.1 Flash memory interface 15.0 GPIOA 8.2 GPIOB 7.7 GPIOC 2.1 GPIOF 1.8 SRAM 1.1 TSC 4.9 All AHB peripherals 49.8 DocID025832 Rev 5 Unit A/MHz STM32F042x4 STM32F042x6 Electrical characteristics Table 32. Peripheral current consumption (continued) Peripheral APB-Bridge APB Typical consumption at 25 C (2) Unit 2.9 ADC(3) 3.9 CAN 12.9 CEC 1.5 CRS 1.0 DBG (MCU Debug Support) 0.2 I2C1 3.6 PWR 1.4 SPI1 8.5 SPI2 6.1 SYSCFG 1.8 TIM1 15.1 TIM2 16.8 TIM3 11.7 TIM14 5.5 TIM16 7.0 TIM17 6.9 USART1 17.8 USART2 5.6 USB 4.9 WWDG 1.4 All APB peripherals A/MHz 136.7 1. The BusMatrix is automatically active when at least one master is ON (CPU, DMA). 2. The APB Bridge is automatically active when at least one peripheral is ON on the Bus. 3. The power consumption of the analog part (IDDA) of peripherals such as ADC is not included. Refer to the tables of characteristics in the subsequent sections. DocID025832 Rev 5 59/117 89 Electrical characteristics 6.3.6 STM32F042x4 STM32F042x6 Wakeup time from low-power mode The wakeup times given in Table 33 are the latency between the event and the execution of the first user instruction. The device goes in low-power mode after the WFE (Wait For Event) instruction, in the case of a WFI (Wait For Interruption) instruction, 16 CPU cycles must be added to the following timings due to the interrupt latency in the Cortex M0 architecture. The SYSCLK clock source setting is kept unchanged after wakeup from Sleep mode. During wakeup from Stop or Standby mode, SYSCLK takes the default setting: HSI 8 MHz. The wakeup source from Sleep and Stop mode is an EXTI line configured in event mode. The wakeup source from Standby mode is the WKUP1 pin (PA0). All timings are derived from tests performed under the ambient temperature and supply voltage conditions summarized in Table 21: General operating conditions.. Table 33. Low-power mode wakeup timings Typ @VDD = VDDA Symbol Parameter Conditions Max Unit = 2.0 V = 2.4 V = 2.7 V tWUSTOP Wakeup from Stop mode Wakeup from tWUSTANDBY Standby mode tWUSLEEP 6.3.7 = 3.3 V Regulator in run mode 3.2 3.1 2.9 2.9 2.8 5 Regulator in low power mode 7.0 5.8 5.2 4.9 4.6 9 - Wakeup from Sleep mode =3V s 60.4 - 55.6 53.5 52 51 4 SYSCLK cycles - External clock source characteristics High-speed external user clock generated from an external source In bypass mode the HSE oscillator is switched off and the input pin is a standard GPIO. The external clock signal has to respect the I/O characteristics in Section 6.3.14. However, the recommended clock input waveform is shown in Figure 15: High-speed external clock source AC timing diagram. Table 34. High-speed external user clock characteristics Symbol 60/117 Parameter(1) Min Typ Max Unit - 8 32 MHz fHSE_ext User external clock source frequency VHSEH OSC_IN input pin high level voltage 0.7 VDDIOx - VDDIOx VHSEL OSC_IN input pin low level voltage VSS - 0.3 VDDIOx 15 - - tw(HSEH) tw(HSEL) OSC_IN high or low time tr(HSE) tf(HSE) OSC_IN rise or fall time V ns DocID025832 Rev 5 - - 20 STM32F042x4 STM32F042x6 Electrical characteristics 1. Guaranteed by design, not tested in production. Figure 15. High-speed external clock source AC timing diagram WZ +6(+ 9+6(+ 9+6(/ WU +6( WI +6( W WZ +6(/ 7+6( 069 Low-speed external user clock generated from an external source In bypass mode the LSE oscillator is switched off and the input pin is a standard GPIO. The external clock signal has to respect the I/O characteristics in Section 6.3.14. However, the recommended clock input waveform is shown in Figure 16. Table 35. Low-speed external user clock characteristics Parameter(1) Symbol fLSE_ext User external clock source frequency Min Typ Max Unit - 32.768 1000 kHz VLSEH OSC32_IN input pin high level voltage 0.7 VDDIOx - VDDIOx VLSEL OSC32_IN input pin low level voltage VSS - 0.3 VDDIOx 450 - - - - 50 tw(LSEH) OSC32_IN high or low time tw(LSEL) tr(LSE) tf(LSE) V ns OSC32_IN rise or fall time 1. Guaranteed by design, not tested in production. Figure 16. Low-speed external clock source AC timing diagram WZ /6(+ 9/6(+ 9/6(/ WU /6( WI /6( WZ /6(/ W 7/6( 069 DocID025832 Rev 5 61/117 89 Electrical characteristics STM32F042x4 STM32F042x6 High-speed external clock generated from a crystal/ceramic resonator The high-speed external (HSE) clock can be supplied with a 4 to 32 MHz crystal/ceramic resonator oscillator. All the information given in this paragraph are based on design simulation results obtained with typical external components specified in Table 36. In the application, the resonator and the load capacitors have to be placed as close as possible to the oscillator pins in order to minimize output distortion and startup stabilization time. Refer to the crystal resonator manufacturer for more details on the resonator characteristics (frequency, package, accuracy). Table 36. HSE oscillator characteristics Symbol fOSC_IN RF Conditions(1) Min(2) Typ Max(2) Unit Oscillator frequency - 4 8 32 MHz Feedback resistor - - 200 - k - - 8.5 VDD = 3.3 V, Rm = 30 , CL = 10 pF@8 MHz - 0.4 - VDD = 3.3 V, Rm = 45 , CL = 10 pF@8 MHz - 0.5 - VDD = 3.3 V, Rm = 30 , CL = 5 pF@32 MHz - 0.8 - VDD = 3.3 V, Rm = 30 , CL = 10 pF@32 MHz - 1 - VDD = 3.3 V, Rm = 30 , CL = 20 pF@32 MHz - 1.5 - Startup 10 - - mA/V VDD is stabilized - 2 - ms Parameter (3) During startup IDD gm tSU(HSE)(4) HSE current consumption Oscillator transconductance Startup time mA 1. Resonator characteristics given by the crystal/ceramic resonator manufacturer. 2. Guaranteed by design, not tested in production. 3. This consumption level occurs during the first 2/3 of the tSU(HSE) startup time 4. tSU(HSE) is the startup time measured from the moment it is enabled (by software) to a stabilized 8 MHz oscillation is reached. This value is measured for a standard crystal resonator and it can vary significantly with the crystal manufacturer For CL1 and CL2, it is recommended to use high-quality external ceramic capacitors in the 5 pF to 20 pF range (Typ.), designed for high-frequency applications, and selected to match the requirements of the crystal or resonator (see Figure 17). CL1 and CL2 are usually the same size. The crystal manufacturer typically specifies a load capacitance which is the series combination of CL1 and CL2. PCB and MCU pin capacitance must be included (10 pF can be used as a rough estimate of the combined pin and board capacitance) when sizing CL1 and CL2. Note: 62/117 For information on selecting the crystal, refer to the application note AN2867 "Oscillator design guide for ST microcontrollers" available from the ST website www.st.com. DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Figure 17. Typical application with an 8 MHz crystal 5HVRQDWRUZLWKLQWHJUDWHG FDSDFLWRUV &/ 26&B,1 0+] UHVRQDWRU &/ 5(;7 I+6( 5) %LDV FRQWUROOHG JDLQ 26&B287 069 1. REXT value depends on the crystal characteristics. Low-speed external clock generated from a crystal resonator The low-speed external (LSE) clock can be supplied with a 32.768 kHz crystal resonator oscillator. All the information given in this paragraph are based on design simulation results obtained with typical external components specified in Table 37. In the application, the resonator and the load capacitors have to be placed as close as possible to the oscillator pins in order to minimize output distortion and startup stabilization time. Refer to the crystal resonator manufacturer for more details on the resonator characteristics (frequency, package, accuracy). Table 37. LSE oscillator characteristics (fLSE = 32.768 kHz) Symbol LSE current consumption IDD Oscillator transconductance gm tSU(LSE) Parameter (3) Startup time Conditions(1) Min(2) Typ Max(2) Unit low drive capability - 0.5 0.9 medium-low drive capability - - 1 medium-high drive capability - - 1.3 high drive capability - - 1.6 low drive capability 5 - - medium-low drive capability 8 - - medium-high drive capability 15 - - high drive capability 25 - - VDDIOx is stabilized - 2 - A A/V s 1. Refer to the note and caution paragraphs below the table, and to the application note AN2867 "Oscillator design guide for ST microcontrollers". 2. Guaranteed by design, not tested in production. 3. tSU(LSE) is the startup time measured from the moment it is enabled (by software) to a stabilized 32.768 kHz oscillation is reached. This value is measured for a standard crystal and it can vary significantly with the crystal manufacturer DocID025832 Rev 5 63/117 89 Electrical characteristics Note: STM32F042x4 STM32F042x6 For information on selecting the crystal, refer to the application note AN2867 "Oscillator design guide for ST microcontrollers" available from the ST website www.st.com. Figure 18. Typical application with a 32.768 kHz crystal 5HVRQDWRUZLWKLQWHJUDWHG FDSDFLWRUV &/ 26&B,1 I/6( 'ULYH SURJUDPPDEOH DPSOLILHU N+] UHVRQDWRU 26&B287 &/ 069 Note: An external resistor is not required between OSC32_IN and OSC32_OUT and it is forbidden to add one. 6.3.8 Internal clock source characteristics The parameters given in Table 38 are derived from tests performed under ambient temperature and supply voltage conditions summarized in Table 21: General operating conditions. The provided curves are characterization results, not tested in production. 64/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics High-speed internal (HSI) RC oscillator Table 38. HSI oscillator characteristics(1) Symbol Parameter fHSI Conditions Min Typ - - Frequency TRIM HSI user trimming step DuCy(HSI) Duty cycle Accuracy of the HSI oscillator ACCHSI - - - (2) 45 IDDA(HSI) Unit 8 - MHz - (2) - % 1 (2) 55 % TA = -40 to 105C (3) -2.8 - 3.8 TA = -10 to 85C -1.9(3) - 2.3(3) TA = 0 to 85C -1.9(3) - 2(3) TA = 0 to 70C -1.3(3) - 2(3) TA = 0 to 55C -1(3) - 2(3) -1 - 1 - 2(2) s 80 100(2) A TA = 25C(4) tsu(HSI) Max HSI oscillator startup time - 1(2) HSI oscillator power consumption - - (3) % 1. VDDA = 3.3 V, TA = -40 to 105C unless otherwise specified. 2. Guaranteed by design, not tested in production. 3. Data based on characterization results, not tested in production. 4. Factory calibrated, parts not soldered. Figure 19. HSI oscillator accuracy characterization results for soldered parts ."9 .*/ 5<$> " 069 DocID025832 Rev 5 65/117 89 Electrical characteristics STM32F042x4 STM32F042x6 High-speed internal 14 MHz (HSI14) RC oscillator (dedicated to ADC) Table 39. HSI14 oscillator characteristics(1) Symbol fHSI14 TRIM Parameter Conditions Min Typ - - 14 Frequency HSI14 user-trimming step DuCy(HSI14) Duty cycle - - - (2) 45 Accuracy of the HSI14 oscillator (factory calibrated) TA = -10 to 85 C TA = 25 C tsu(HSI14) IDDA(HSI14) - MHz (2) - % 1 55 (2) % (3) % (3) - 5.1 -3.2(3) - 3.1(3) % -2.5 - 2.3 (3) % -1 (3) TA = 0 to 70 C Unit - TA = -40 to 105 C -4.2 ACCHSI14 Max HSI14 oscillator startup time - 1(2) HSI14 oscillator power consumption - - - 1 % - 2(2) s 100 150(2) A 1. VDDA = 3.3 V, TA = -40 to 105 C unless otherwise specified. 2. Guaranteed by design, not tested in production. 3. Data based on characterization results, not tested in production. Figure 20. HSI14 oscillator accuracy characterization results 0$; 0,1 7>&@ $ 069 66/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics High-speed internal 48 MHz (HSI48) RC oscillator Table 40. HSI48 oscillator characteristics(1) Symbol fHSI48 TRIM Parameter Conditions Min Typ Max Unit - - 48 - MHz Frequency HSI48 user-trimming step (2) - DuCy(HSI48) Duty cycle 0.09 - 45 TA = -40 to 105 C ACCHSI48 TA = -10 to 85 C Accuracy of the HSI48 oscillator (factory calibrated) T = 0 to 70 C A IDDA(HSI48) 0.14 - % (2) % (3) 0.2 55 (3) - 4.7 % -4.1(3) - 3.7(3) % - (3) % -4.9 (3) -3.8 TA = 25 C tsu(HSI48) (2) (2) -2.8 3.4 - 2.9 % s A HSI48 oscillator startup time - - - 6(2) HSI48 oscillator power consumption - - 312 350(2) 1. VDDA = 3.3 V, TA = -40 to 105 C unless otherwise specified. 2. Guaranteed by design, not tested in production. 3. Data based on characterization results, not tested in production. Figure 21. HSI48 oscillator accuracy characterization results 0$; 0,1 7>&@ $ 069 DocID025832 Rev 5 67/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Low-speed internal (LSI) RC oscillator Table 41. LSI oscillator characteristics(1) Symbol Parameter fLSI tsu(LSI) Min Typ Max Unit 30 40 50 kHz LSI oscillator startup time - - 85 s LSI oscillator power consumption - 0.75 1.2 A Frequency (2) IDDA(LSI)(2) 1. VDDA = 3.3 V, TA = -40 to 105 C unless otherwise specified. 2. Guaranteed by design, not tested in production. 6.3.9 PLL characteristics The parameters given in Table 42 are derived from tests performed under ambient temperature and supply voltage conditions summarized in Table 21: General operating conditions. Table 42. PLL characteristics Value Symbol fPLL_IN fPLL_OUT tLOCK JitterPLL Parameter Unit Min Typ Max 1(2) 8.0 24(2) MHz PLL input clock duty cycle (2) 40 - 60(2) % PLL multiplier output clock 16(2) - 48 MHz PLL lock time - - 200(2) s Cycle-to-cycle jitter - - 300(2) ps PLL input clock(1) 1. Take care to use the appropriate multiplier factors to obtain PLL input clock values compatible with the range defined by fPLL_OUT. 2. Guaranteed by design, not tested in production. 6.3.10 Memory characteristics Flash memory The characteristics are given at TA = -40 to 105 C unless otherwise specified. Table 43. Flash memory characteristics Min Typ Max(1) Unit 16-bit programming time TA = - 40 to +105 C 40 53.5 60 s Page (1 KB) erase time TA = - 40 to +105 C 20 - 40 ms tME Mass erase time TA = - 40 to +105 C 20 - 40 ms IDD Supply current Write mode - - 10 mA Erase mode - - 12 mA Symbol tprog tERASE Parameter Conditions 1. Guaranteed by design, not tested in production. 68/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Table 44. Flash memory endurance and data retention Symbol NEND Parameter Endurance Conditions TA = -40 to +105 C 1 tRET Data retention kcycle(2) Min(1) Unit 10 kcycle at TA = 85 C 30 at TA = 105 C 10 10 kcycle(2) at TA = 55 C 20 1 kcycle (2) Year 1. Data based on characterization results, not tested in production. 2. Cycling performed over the whole temperature range. 6.3.11 EMC characteristics Susceptibility tests are performed on a sample basis during device characterization. Functional EMS (electromagnetic susceptibility) While a simple application is executed on the device (toggling 2 LEDs through I/O ports). the device is stressed by two electromagnetic events until a failure occurs. The failure is indicated by the LEDs: * Electrostatic discharge (ESD) (positive and negative) is applied to all device pins until a functional disturbance occurs. This test is compliant with the IEC 61000-4-2 standard. * FTB: A Burst of Fast Transient voltage (positive and negative) is applied to VDD and VSS through a 100 pF capacitor, until a functional disturbance occurs. This test is compliant with the IEC 61000-4-4 standard. A device reset allows normal operations to be resumed. The test results are given in Table 45. They are based on the EMS levels and classes defined in application note AN1709. Table 45. EMS characteristics Symbol Parameter Conditions Level/ Class VFESD VDD = 3.3 V, LQFP48, TA = +25 C, Voltage limits to be applied on any I/O pin fHCLK = 48 MHz, to induce a functional disturbance conforming to IEC 61000-4-2 3B VEFTB Fast transient voltage burst limits to be applied through 100 pF on VDD and VSS pins to induce a functional disturbance VDD = 3.3 V, LQFP48, TA = +25C, fHCLK = 48 MHz, conforming to IEC 61000-4-4 4B Designing hardened software to avoid noise problems EMC characterization and optimization are performed at component level with a typical application environment and simplified MCU software. It should be noted that good EMC performance is highly dependent on the user application and the software in particular. Therefore it is recommended that the user applies EMC software optimization and prequalification tests in relation with the EMC level requested for his application. DocID025832 Rev 5 69/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Software recommendations The software flowchart must include the management of runaway conditions such as: * Corrupted program counter * Unexpected reset * Critical Data corruption (for example control registers) Prequalification trials Most of the common failures (unexpected reset and program counter corruption) can be reproduced by manually forcing a low state on the NRST pin or the Oscillator pins for 1 second. To complete these trials, ESD stress can be applied directly on the device, over the range of specification values. When unexpected behavior is detected, the software can be hardened to prevent unrecoverable errors occurring (see application note AN1015). Electromagnetic Interference (EMI) The electromagnetic field emitted by the device are monitored while a simple application is executed (toggling 2 LEDs through the I/O ports). This emission test is compliant with IEC 61967-2 standard which specifies the test board and the pin loading. Table 46. EMI characteristics Symbol Parameter SEMI 6.3.12 Conditions Monitored frequency band 0.1 to 30 MHz VDD = 3.6 V, TA = 25 C, 30 to 130 MHz LQFP48 package Peak level compliant with 130 MHz to 1 GHz IEC 61967-2 EMI Level Max vs. [fHSE/fHCLK] Unit 8/48 MHz -9 9 dBV 17 3 - Electrical sensitivity characteristics Based on three different tests (ESD, LU) using specific measurement methods, the device is stressed in order to determine its performance in terms of electrical sensitivity. Electrostatic discharge (ESD) Electrostatic discharges (a positive then a negative pulse separated by 1 second) are applied to the pins of each sample according to each pin combination. The sample size depends on the number of supply pins in the device (3 parts x (n+1) supply pins). This test conforms to the JESD22-A114/C101 standard. 70/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Table 47. ESD absolute maximum ratings Symbol Ratings Conditions Packages Class Maximum value(1) Unit VESD(HBM) Electrostatic discharge voltage TA = +25 C, conforming (human body model) to JESD22-A114 All 2 2000 V VESD(CDM) Electrostatic discharge voltage TA = +25 C, conforming (charge device model) to ANSI/ESD STM5.3.1 All C4 500 V 1. Data based on characterization results, not tested in production. Static latch-up Two complementary static tests are required on six parts to assess the latch-up performance: * A supply overvoltage is applied to each power supply pin. * A current injection is applied to each input, output and configurable I/O pin. These tests are compliant with EIA/JESD 78A IC latch-up standard. Table 48. Electrical sensitivities Symbol LU 6.3.13 Parameter Static latch-up class Conditions TA = +105 C conforming to JESD78A Class II level A I/O current injection characteristics As a general rule, current injection to the I/O pins, due to external voltage below VSS or above VDDIOx (for standard, 3.3 V-capable I/O pins) should be avoided during normal product operation. However, in order to give an indication of the robustness of the microcontroller in cases when abnormal injection accidentally happens, susceptibility tests are performed on a sample basis during device characterization. Functional susceptibility to I/O current injection While a simple application is executed on the device, the device is stressed by injecting current into the I/O pins programmed in floating input mode. While current is injected into the I/O pin, one at a time, the device is checked for functional failures. The failure is indicated by an out of range parameter: ADC error above a certain limit (higher than 5 LSB TUE), out of conventional limits of induced leakage current on adjacent pins (out of the -5 A/+0 A range) or other functional failure (for example reset occurrence or oscillator frequency deviation). The characterization results are given in Table 49. Negative induced leakage current is caused by negative injection and positive induced leakage current is caused by positive injection. DocID025832 Rev 5 71/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Table 49. I/O current injection susceptibility Functional susceptibility Symbol Description Unit Negative Positive injection injection IINJ 6.3.14 Injected current on PA12 pin -0 +5 Injected current on PA9, PB3, PB13, PF11 pins with induced leakage current on adjacent pins less than 50 A -5 NA Injected current on PB0, PB1 and all other FT and FTf pins -5 NA Injected current on all other TC, TTa and RST pins -5 +5 mA I/O port characteristics General input/output characteristics Unless otherwise specified, the parameters given in Table 50 are derived from tests performed under the conditions summarized in Table 21: General operating conditions. All I/Os are designed as CMOS- and TTL-compliant. Table 50. I/O static characteristics Symbol VIL Parameter Low level input voltage Conditions Min Typ Max TC and TTa I/O - - 0.3 VDDIOx+0.07(1) FT and FTf I/O - - 0.475 VDDIOx-0.2(1) All I/Os - - 0.3 VDDIOx +0.398(1) - - +0.2(1) - - 0.7 VDDIOx - - - 200(1) - FT and FTf I/O - (1) 100 - TC, FT and FTf I/O TTa in digital mode VSS VIN VDDIOx - - 0.1 TTa in digital mode VDDIOx VIN VDDA - - 1 TTa in analog mode VSS VIN VDDA - - 0.2 FT and FTf I/O VDDIOx VIN 5 V - - 10 25 40 55 TC and TTa I/O VIH High level input voltage FT and FTf I/O 0.5 VDDIOx All I/Os Vhys Ilkg RPU 72/117 Schmitt trigger hysteresis Input leakage current(2) Weak pull-up equivalent resistor (3) TC and TTa I/O VIN = VSS 0.445 VDDIOx DocID025832 Rev 5 Unit V V mV A k STM32F042x4 STM32F042x6 Electrical characteristics Table 50. I/O static characteristics (continued) Symbol Parameter RPD Weak pull-down equivalent resistor(3) CIO I/O pin capacitance Conditions VIN = - VDDIOx - Min Typ Max Unit 25 40 55 k - 5 - pF 1. Data based on design simulation only. Not tested in production. 2. The leakage could be higher than the maximum value, if negative current is injected on adjacent pins. Refer to Table 49: I/O current injection susceptibility. 3. Pull-up and pull-down resistors are designed with a true resistance in series with a switchable PMOS/NMOS. This PMOS/NMOS contribution to the series resistance is minimal (~10% order). All I/Os are CMOS- and TTL-compliant (no software configuration required). Their characteristics cover more than the strict CMOS-technology or TTL parameters. The coverage of these requirements is shown in Figure 22 for standard I/Os, and in Figure 23 for 5 V-tolerant I/Os. The following curves are design simulation results, not tested in production. DocID025832 Rev 5 73/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Figure 22. TC and TTa I/O input characteristics 7(67('5$1*( 77/VWDQGDUGUHTXLUHPHQW HQW LUHP HTX DUGU QG 6VWD 2 &0 9,1 9 9 [ '',2 9 ,+PLQ 81'(),1(',13875$1*( ',2[ 9' 9,+PLQ 9'',2[ 9,/PD[ XLUHPHQW WDQGDUGUHT V 6 2 0 & 9'',2[ 9,/PD[ 77/VWDQGDUGUHTXLUHPHQW 7(67('5$1*( 9'',2[ 9 06Y9 Figure 23. Five volt tolerant (FT and FTf) I/O input characteristics 7(67('5$1*( 77/VWDQGDUGUHTXLUHPHQW HQW LUHP 9,1 9 9 9 ,+PLQ 81'(),1(',13875$1*( '',2[ 9 9,/PD[ QG 6VWD &02 [ '',2 9 9,+PLQ HTX DUGU '',2[ 77/VWDQGDUGUHTXLUHPHQW XLUHPHQW QGDUGUHT WD &026V [ 9'',2 9,/PD[ 7(67('5$1*( 9'',2[ 9 06Y9 74/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Output driving current The GPIOs (general purpose input/outputs) can sink or source up to +/-8 mA, and sink or source up to +/- 20 mA (with a relaxed VOL/VOH). In the user application, the number of I/O pins which can drive current must be limited to respect the absolute maximum rating specified in Section 6.2: * The sum of the currents sourced by all the I/Os on VDDIOx, plus the maximum consumption of the MCU sourced on VDD, cannot exceed the absolute maximum rating IVDD (see Table 18: Voltage characteristics). * The sum of the currents sunk by all the I/Os on VSS, plus the maximum consumption of the MCU sunk on VSS, cannot exceed the absolute maximum rating IVSS (see Table 18: Voltage characteristics). Output voltage levels Unless otherwise specified, the parameters given in the table below are derived from tests performed under the ambient temperature and supply voltage conditions summarized in Table 21: General operating conditions. All I/Os are CMOS- and TTL-compliant (FT, TTa or TC unless otherwise specified). Table 51. Output voltage characteristics(1) Symbol Parameter VOL Output low level voltage for an I/O pin VOH Output high level voltage for an I/O pin VOL Output low level voltage for an I/O pin VOH Output high level voltage for an I/O pin VOL(3) Output low level voltage for an I/O pin VOH(3) Output high level voltage for an I/O pin VOL(3) Output low level voltage for an I/O pin VOH(3) Output high level voltage for an I/O pin VOL(4) Output low level voltage for an I/O pin VOH(4) Output high level voltage for an I/O pin VOLFm+(3) Output low level voltage for an FTf I/O pin in Fm+ mode Conditions Min Max CMOS port(2) |IIO| = 8 mA VDDIOx 2.7 V - 0.4 VDDIOx-0.4 - - 0.4 2.4 - - 1.3 VDDIOx-1.3 - - 0.4 VDDIOx-0.4 - - 0.4 V VDDIOx-0.4 - V |IIO| = 20 mA VDDIOx 2.7 V - 0.4 V |IIO| = 10 mA - 0.4 V TTL port(2) |IIO| = 8 mA VDDIOx 2.7 V |IIO| = 20 mA VDDIOx 2.7 V |IIO| = 6 mA VDDIOx 2 V |IIO| = 4 mA Unit V V V V 1. The IIO current sourced or sunk by the device must always respect the absolute maximum rating specified in Table 18: Voltage characteristics, and the sum of the currents sourced or sunk by all the I/Os (I/O ports and control pins) must always respect the absolute maximum ratings IIO. 2. TTL and CMOS outputs are compatible with JEDEC standards JESD36 and JESD52. 3. Data based on characterization results. Not tested in production. 4. Data based on characterization results. Not tested in production. DocID025832 Rev 5 75/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Input/output AC characteristics The definition and values of input/output AC characteristics are given in Figure 24 and Table 52, respectively. Unless otherwise specified, the parameters given are derived from tests performed under the ambient temperature and supply voltage conditions summarized in Table 21: General operating conditions. Table 52. I/O AC characteristics(1)(2) OSPEEDRy [1:0] value(1) Symbol Parameter Conditions Min Max Unit - 2 MHz - 125 - 125 - 1 - 125 - 125 - 10 - 25 - 25 - 4 - 62.5 - 62.5 CL = 30 pF, VDDIOx 2.7 V - 50 CL = 50 pF, VDDIOx 2.7 V - 30 CL = 50 pF, 2 V VDDIOx < 2.7 V - 20 CL = 50 pF, VDDIOx < 2 V - 10 CL = 30 pF, VDDIOx 2.7 V - 5 CL = 50 pF, VDDIOx 2.7 V - 8 CL = 50 pF, 2 V VDDIOx < 2.7 V - 12 CL = 50 pF, VDDIOx < 2 V - 25 CL = 30 pF, VDDIOx 2.7 V - 5 CL = 50 pF, VDDIOx 2.7 V - 8 CL = 50 pF, 2 V VDDIOx < 2.7 V - 12 CL = 50 pF, VDDIOx < 2 V - 25 fmax(IO)out Maximum frequency(3) x0 tf(IO)out Output fall time tr(IO)out Output rise time CL = 50 pF, VDDIOx 2 V fmax(IO)out Maximum frequency(3) tf(IO)out Output fall time tr(IO)out Output rise time CL = 50 pF, VDDIOx < 2 V fmax(IO)out Maximum frequency(3) 01 tf(IO)out Output fall time tr(IO)out Output rise time CL = 50 pF, VDDIOx 2 V fmax(IO)out Maximum frequency(3) tf(IO)out Output fall time tr(IO)out Output rise time CL = 50 pF, VDDIOx < 2 V fmax(IO)out Maximum frequency(3) 11 tf(IO)out tr(IO)out 76/117 Output fall time Output rise time DocID025832 Rev 5 ns MHz ns MHz ns MHz ns MHz ns STM32F042x4 STM32F042x6 Electrical characteristics Table 52. I/O AC characteristics(1)(2) (continued) OSPEEDRy [1:0] value(1) Symbol Parameter Conditions fmax(IO)out Maximum frequency(3) Fm+ configuration (4) - tf(IO)out Output fall time tr(IO)out Output rise time CL = 50 pF, VDDIOx 2 V fmax(IO)out Maximum frequency(3) tf(IO)out Output fall time CL = 50 pF, VDDIOx < 2 V tr(IO)out Output rise time tEXTIpw Pulse width of external signals detected by the EXTI controller - Min Max Unit - 2 MHz - 12 - 34 - 0.5 - 16 - 44 10 - ns MHz ns ns 1. The I/O speed is configured using the OSPEEDRx[1:0] bits. Refer to the STM32F0xxxx RM0091 reference manual for a description of GPIO Port configuration register. 2. Guaranteed by design, not tested in production. 3. The maximum frequency is defined in Figure 24. 4. When Fm+ configuration is set, the I/O speed control is bypassed. Refer to the STM32F0xxxx reference manual RM0091 for a detailed description of Fm+ I/O configuration. Figure 24. I/O AC characteristics definition W I ,2 RXW W U ,2 RXW 7 0D[LPXPIUHTXHQF\LVDFKLHYHGLI WW U I 7DQGLIWKHGXW\F\FOHLV ZKHQORDGHGE\& - VHHWKHWDEOH,2$&FKDUDFWHULVWLFVGHILQLWLRQ 069 6.3.15 NRST pin characteristics The NRST pin input driver uses the CMOS technology. It is connected to a permanent pullup resistor, RPU. Unless otherwise specified, the parameters given in the table below are derived from tests performed under the ambient temperature and supply voltage conditions summarized in Table 21: General operating conditions. Table 53. NRST pin characteristics Symbol Parameter Conditions Min Typ Max VIL(NRST) NRST input low level voltage - - - 0.3 VDD+0.07(1) VIH(NRST) NRST input high level voltage - 0.445 VDD+0.398(1) - - DocID025832 Rev 5 Unit V 77/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Table 53. NRST pin characteristics (continued) Symbol Parameter Conditions Min Typ Max Unit Vhys(NRST) NRST Schmitt trigger voltage hysteresis - - 200 - mV RPU Weak pull-up equivalent resistor(2) VIN = VSS 25 40 55 k VF(NRST) NRST input filtered pulse - - - 100(1) ns 2.7 < VDD < 3.6 300(3) - - 2.0 < VDD < 3.6 (3) - - VNF(NRST) NRST input not filtered pulse 500 ns 1. Data based on design simulation only. Not tested in production. 2. The pull-up is designed with a true resistance in series with a switchable PMOS. This PMOS contribution to the series resistance is minimal (~10% order). 3. Data based on design simulation only. Not tested in production. Figure 25. Recommended NRST pin protection ([WHUQDO UHVHWFLUFXLW 9'' 538 1567 ,QWHUQDOUHVHW )LOWHU ) 069 1. The external capacitor protects the device against parasitic resets. 2. The user must ensure that the level on the NRST pin can go below the VIL(NRST) max level specified in Table 53: NRST pin characteristics. Otherwise the reset will not be taken into account by the device. 6.3.16 12-bit ADC characteristics Unless otherwise specified, the parameters given in Table 54 are derived from tests performed under the conditions summarized in Table 21: General operating conditions. Note: It is recommended to perform a calibration after each power-up. Table 54. ADC characteristics Symbol Parameter Conditions Min Typ Max Unit VDDA Analog supply voltage for ADC ON - 2.4 - 3.6 V VDDA = 3.3 V - 0.9 - mA - 0.6 - 14 MHz 12-bit resolution 0.043 - 1 MHz IDDA (ADC) Current consumption of the ADC(1) fADC ADC clock frequency fS(2) Sampling rate 78/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Table 54. ADC characteristics (continued) Symbol fTRIG(2) Parameter Conditions Min Typ Max Unit External trigger frequency fADC = 14 MHz, 12-bit resolution - - 823 kHz 12-bit resolution - - 17 1/fADC VAIN Conversion voltage range - 0 - VDDA V RAIN(2) External input impedance See Equation 1 and Table 55 for details - - 50 k RADC(2) Sampling switch resistance - - - 1 k CADC(2) Internal sample and hold capacitor - - - 8 pF tCAL(2)(3) Calibration time WLATENCY(2)(4) tlatr(2) ADC_DR register ready latency fADC = 14 MHz 5.9 s - 83 1/fADC ADC clock = HSI14 1.5 ADC cycles + 2 fPCLK cycles - 1.5 ADC cycles + 3 fPCLK cycles - ADC clock = PCLK/2 - 4.5 - fPCLK cycle ADC clock = PCLK/4 - 8.5 - fPCLK cycle fADC = fPCLK/2 = 14 MHz 0.196 s fADC = fPCLK/2 5.5 1/fPCLK 0.219 s 10.5 1/fPCLK Trigger conversion latency fADC = fPCLK/4 = 12 MHz fADC = fPCLK/4 JitterADC tS(2) fADC = fHSI14 = 14 MHz 0.179 - 0.250 s fADC = fHSI14 - 1 - 1/fHSI14 fADC = 14 MHz 0.107 - 17.1 s - 1.5 - 239.5 1/fADC ADC jitter on trigger conversion Sampling time tSTAB(2) Stabilization time tCONV(2) Total conversion time (including sampling time) fADC = 14 MHz, 12-bit resolution 12-bit resolution 14 1 - 1/fADC 18 14 to 252 (tS for sampling +12.5 for successive approximation) s 1/fADC 1. During conversion of the sampled value (12.5 x ADC clock period), an additional consumption of 100 A on IDDA and 60 A on IDD should be taken into account. 2. Guaranteed by design, not tested in production. 3. Specified value includes only ADC timing. It does not include the latency of the register access. 4. This parameter specify latency for transfer of the conversion result to the ADC_DR register. EOC flag is set at this time. DocID025832 Rev 5 79/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Equation 1: RAIN max formula TS - - R ADC R AIN < --------------------------------------------------------------N+2 f ADC x C ADC x ln ( 2 ) The formula above (Equation 1) is used to determine the maximum external impedance allowed for an error below 1/4 of LSB. Here N = 12 (from 12-bit resolution). Table 55. RAIN max for fADC = 14 MHz Ts (cycles) tS (s) RAIN max (k)(1) 1.5 0.11 0.4 7.5 0.54 5.9 13.5 0.96 11.4 28.5 2.04 25.2 41.5 2.96 37.2 55.5 3.96 50 71.5 5.11 NA 239.5 17.1 NA 1. Guaranteed by design, not tested in production. Table 56. ADC accuracy(1)(2)(3) Symbol Parameter Test conditions Typ Max(4) 1.3 2 1 1.5 0.5 1.5 0.7 1 ET Total unadjusted error EO Offset error EG Gain error ED Differential linearity error EL Integral linearity error 0.8 1.5 ET Total unadjusted error 3.3 4 EO Offset error 1.9 2.8 EG Gain error 2.8 3 ED Differential linearity error 0.7 1.3 EL Integral linearity error 1.2 1.7 ET Total unadjusted error 3.3 4 EO Offset error 1.9 2.8 EG Gain error 2.8 3 ED Differential linearity error 0.7 1.3 EL Integral linearity error 1.2 1.7 fPCLK = 48 MHz, fADC = 14 MHz, RAIN < 10 k VDDA = 3 V to 3.6 V TA = 25 C fPCLK = 48 MHz, fADC = 14 MHz, RAIN < 10 k VDDA = 2.7 V to 3.6 V TA = - 40 to 105 C fPCLK = 48 MHz, fADC = 14 MHz, RAIN < 10 k VDDA = 2.4 V to 3.6 V TA = 25 C 1. ADC DC accuracy values are measured after internal calibration. 80/117 DocID025832 Rev 5 Unit LSB LSB LSB STM32F042x4 STM32F042x6 Electrical characteristics 2. ADC Accuracy vs. Negative Injection Current: Injecting negative current on any of the standard (non-robust) analog input pins should be avoided as this significantly reduces the accuracy of the conversion being performed on another analog input. It is recommended to add a Schottky diode (pin to ground) to standard analog pins which may potentially inject negative current. Any positive injection current within the limits specified for IINJ(PIN) and IINJ(PIN) in Section 6.3.14 does not affect the ADC accuracy. 3. Better performance may be achieved in restricted VDDA, frequency and temperature ranges. 4. Data based on characterization results, not tested in production. Figure 26. ADC accuracy characteristics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igure 27. Typical connection diagram using the ADC 9''$ 6DPSOHDQGKROG$'& FRQYHUWHU 97 5$,1 9$,1 5$'& $,1[ &SDUDVLWLF 97 ,/ $ ELW FRQYHUWHU &$'& 069 1. Refer to Table 54: ADC characteristics for the values of RAIN, RADC and CADC. 2. Cparasitic represents the capacitance of the PCB (dependent on soldering and PCB layout quality) plus the pad capacitance (roughly 7 pF). A high Cparasitic value will downgrade conversion accuracy. To remedy this, fADC should be reduced. General PCB design guidelines Power supply decoupling should be performed as shown in Figure 13: Power supply scheme. The 10 nF capacitor should be ceramic (good quality) and it should be placed as close as possible to the chip. DocID025832 Rev 5 81/117 89 Electrical characteristics 6.3.17 STM32F042x4 STM32F042x6 Temperature sensor characteristics Table 57. TS characteristics Symbol Parameter TL(1) Avg_Slope Min Typ Max Unit - 1 2 C 4.0 4.3 4.6 mV/C 1.34 1.43 1.52 V VSENSE linearity with temperature (1) V30 Average slope (2) Voltage at 30 C ( 5 C) tSTART(1) ADC_IN16 buffer startup time - - 10 s tS_temp(1) ADC sampling time when reading the temperature 4 - - s 1. Guaranteed by design, not tested in production. 2. Measured at VDDA = 3.3 V 10 mV. The V30 ADC conversion result is stored in the TS_CAL1 byte. Refer to Table 3: Temperature sensor calibration values. 6.3.18 VBAT monitoring characteristics Table 58. VBAT monitoring characteristics Symbol Parameter Min Typ Max Unit R Resistor bridge for VBAT - 2 x 50 - k Q Ratio on VBAT measurement - 2 - - Error on Q -1 - +1 % ADC sampling time when reading the VBAT 4 - - s Er(1) tS_vbat(1) 1. Guaranteed by design, not tested in production. 6.3.19 Timer characteristics The parameters given in the following tables are guaranteed by design. Refer to Section 6.3.14: I/O port characteristics for details on the input/output alternate function characteristics (output compare, input capture, external clock, PWM output). Table 59. TIMx characteristics Symbol Parameter tres(TIM) Timer resolution time fEXT Timer external clock frequency on CH1 to CH4 16-bit timer maximum period tMAX_COUNT 32-bit counter maximum period 82/117 Conditions Min Typ Max Unit - - 1 - tTIMxCLK fTIMxCLK = 48 MHz - 20.8 - ns - - fTIMxCLK/2 - MHz fTIMxCLK = 48 MHz - 24 - MHz - - 216 - tTIMxCLK fTIMxCLK = 48 MHz - 1365 - s - - 232 - tTIMxCLK fTIMxCLK = 48 MHz - 89.48 - s DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Table 60. IWDG min/max timeout period at 40 kHz (LSI)(1) Prescaler divider PR[2:0] bits Min timeout RL[11:0]= 0x000 Max timeout RL[11:0]= 0xFFF /4 0 0.1 409.6 /8 1 0.2 819.2 /16 2 0.4 1638.4 /32 3 0.8 3276.8 /64 4 1.6 6553.6 /128 5 3.2 13107.2 /256 6 or 7 6.4 26214.4 Unit ms 1. These timings are given for a 40 kHz clock but the microcontroller internal RC frequency can vary from 30 to 60 kHz. Moreover, given an exact RC oscillator frequency, the exact timings still depend on the phasing of the APB interface clock versus the LSI clock so that there is always a full RC period of uncertainty. Table 61. WWDG min/max timeout value at 48 MHz (PCLK) 6.3.20 Prescaler WDGTB Min timeout value Max timeout value 1 0 0.0853 5.4613 2 1 0.1706 10.9226 4 2 0.3413 21.8453 8 3 0.6826 43.6906 Unit ms Communication interfaces I2C interface characteristics The I2C interface meets the timings requirements of the I2C-bus specification and user manual rev. 03 for: * Standard-mode (Sm): with a bit rate up to 100 kbit/s * Fast-mode (Fm): with a bit rate up to 400 kbit/s * Fast-mode Plus (Fm+): with a bit rate up to 1 Mbit/s. The I2C timings requirements are guaranteed by design when the I2Cx peripheral is properly configured (refer to Reference manual). The SDA and SCL I/O requirements are met with the following restrictions: the SDA and SCL I/O pins are not "true" open-drain. When configured as open-drain, the PMOS connected between the I/O pin and VDDIOx is disabled, but is still present. Only FTf I/O pins support Fm+ low level output current maximum requirement. Refer to Section 6.3.14: I/O port characteristics for the I2C I/Os characteristics. All I2C SDA and SCL I/Os embed an analog filter. Refer to the table below for the analog filter characteristics: DocID025832 Rev 5 83/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Table 62. I2C analog filter characteristics(1) Symbol tAF Parameter Maximum width of spikes that are suppressed by the analog filter Min Max Unit 50(2) 260(3) ns 1. Guaranteed by design, not tested in production. 2. Spikes with widths below tAF(min) are filtered. 3. Spikes with widths above tAF(max) are not filtered SPI/I2S characteristics Unless otherwise specified, the parameters given in Table 63 for SPI or in Table 64 for I2S are derived from tests performed under the ambient temperature, fPCLKx frequency and supply voltage conditions summarized in Table 21: General operating conditions. Refer to Section 6.3.14: I/O port characteristics for more details on the input/output alternate function characteristics (NSS, SCK, MOSI, MISO for SPI and WS, CK, SD for I2S). Table 63. SPI characteristics(1) Symbol fSCK 1/tc(SCK) Parameter SPI clock frequency Conditions Min Max Master mode - 18 Slave mode - 18 - 6 tr(SCK) tf(SCK) SPI clock rise and fall time Capacitive load: C = 15 pF tsu(NSS) NSS setup time Slave mode 4Tpclk - th(NSS) NSS hold time Slave mode 2Tpclk + 10 - SCK high and low time Master mode, fPCLK = 36 MHz, presc = 4 Tpclk/2 -2 Tpclk/2 + 1 Master mode 4 - Slave mode 5 - Master mode 4 - Slave mode 5 - Data output access time Slave mode, fPCLK = 20 MHz 0 3Tpclk Data output disable time Slave mode 0 18 tv(SO) Data output valid time Slave mode (after enable edge) - 22.5 tv(MO) Data output valid time Master mode (after enable edge) - 6 Slave mode (after enable edge) 11.5 - Master mode (after enable edge) 2 - Slave mode 25 75 tw(SCKH) tw(SCKL) tsu(MI) tsu(SI) th(MI) th(SI) ta(SO)(2) tdis(SO) (3) th(SO) th(MO) DuCy(SCK) Data input setup time Data input hold time Data output hold time SPI slave input clock duty cycle Unit MHz ns ns % 1. Data based on characterization results, not tested in production. 2. Min time is for the minimum time to drive the output and the max time is for the maximum time to validate the data. 3. Min time is for the minimum time to invalidate the output and the max time is for the maximum time to put the data in Hi-Z 84/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics Figure 28. SPI timing diagram - slave mode and CPHA = 0 166LQSXW WF 6&. 6&.LQSXW WVX 166 WK 166 WZ 6&.+ WU 6&. &3+$ &32/ &3+$ &32/ WD 62 WZ 6&./ 0,62RXWSXW WY 62 WK 62 )LUVWELW287 WI 6&. 1H[WELWV287 WGLV 62 /DVWELW287 WK 6, WVX 6, 026,LQSXW )LUVWELW,1 1H[WELWV,1 /DVWELW,1 06Y9 Figure 29. SPI timing diagram - slave mode and CPHA = 1 166LQSXW 6&.LQSXW WF 6&. WVX 166 WZ 6&.+ WD 62 WZ 6&./ WI 6&. WK 166 &3+$ &32/ &3+$ &32/ 0,62RXWSXW )LUVWELW287 WVX 6, 026,LQSXW WY 62 WK 62 1H[WELWV287 WU 6&. WGLV 62 /DVWELW287 WK 6, )LUVWELW,1 1H[WELWV,1 /DVWELW,1 06Y9 1. Measurement points are done at CMOS levels: 0.3 VDD and 0.7 VDD. DocID025832 Rev 5 85/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Figure 30. SPI timing diagram - master mode +LJK 166LQSXW 6&.2XWSXW &3+$ &32/ 6&.2XWSXW WF 6&. &3+$ &32/ &3+$ &32/ &3+$ &32/ WZ 6&.+ WZ 6&./ WVX 0, 0,62 ,13 87 WU 6&. WI 6&. %,7,1 06%,1 /6%,1 WK 0, 026, 287387 % , 7287 06%287 WY 02 /6%287 WK 02 DLF 1. Measurement points are done at CMOS levels: 0.3 VDD and 0.7 VDD. Table 64. I2S characteristics(1) Symbol fCK 1/tc(CK) Parameter I2S clock frequency Conditions Master mode (data: 16 bits, Audio frequency = 48 kHz) Slave mode tr(CK) I2S clock rise time tf(CK) I2S clock fall time Capacitive load CL = 15 pF Min Max 1.597 1.601 0 6.5 - 10 - 12 306 - 312 - tw(CKH) I2S tw(CKL) 2 I S clock low time Master fPCLK= 16 MHz, audio frequency = 48 kHz tv(WS) WS valid time Master mode 2 - th(WS) WS hold time Master mode 2 - tsu(WS) WS setup time Slave mode 7 - th(WS) WS hold time Slave mode 0 - Slave mode 25 75 DuCy(SCK) 86/117 I2S clock high time slave input clock duty cycle DocID025832 Rev 5 Unit MHz ns % STM32F042x4 STM32F042x6 Electrical characteristics Table 64. I2S characteristics(1) (continued) Symbol tsu(SD_MR) tsu(SD_SR) th(SD_MR) th(SD_SR) Parameter Data input setup time (2) (2) tv(SD_MT)(2) tv(SD_ST)(2) th(SD_MT) th(SD_ST) Data input hold time Data output valid time Data output hold time Conditions Min Max Master receiver 6 - Slave receiver 2 - Master receiver 4 - Slave receiver 0.5 - Master transmitter - 4 Slave transmitter - 20 Master transmitter 0 - Slave transmitter 13 - Unit ns 1. Data based on design simulation and/or characterization results, not tested in production. 2. Depends on fPCLK. For example, if fPCLK = 8 MHz, then TPCLK = 1/fPLCLK = 125 ns. Figure 31. I2S slave timing diagram (Philips protocol) &.,QSXW WF &. &32/ &32/ WZ &.+ WK :6 WZ &./ :6LQSXW WY 6'B67 WVX :6 6'WUDQVPLW /6%WUDQVPLW 06%WUDQVPLW WVX 6'B65 6'UHFHLYH /6%UHFHLYH WK 6'B67 %LWQWUDQVPLW WK 6'B65 06%UHFHLYH %LWQUHFHLYH /6%UHFHLYH 06Y9 1. Measurement points are done at CMOS levels: 0.3 x VDDIOx and 0.7 x VDDIOx. 2. LSB transmit/receive of the previously transmitted byte. No LSB transmit/receive is sent before the first byte. DocID025832 Rev 5 87/117 89 Electrical characteristics STM32F042x4 STM32F042x6 Figure 32. I2S master timing diagram (Philips protocol) WI &. WU &. &.RXWSXW WF &. &32/ WZ &.+ &32/ WY :6 WK :6 WZ &./ :6RXWSXW WY 6'B07 6'WUDQVPLW /6%WUDQVPLW 06%WUDQVPLW /6%UHFHLYH /6%WUDQVPLW WK 6'B05 WVX 6'B05 6'UHFHLYH %LWQWUDQVPLW WK 6'B07 06%UHFHLYH %LWQUHFHLYH /6%UHFHLYH 06Y9 1. Data based on characterization results, not tested in production. 2. LSB transmit/receive of the previously transmitted byte. No LSB transmit/receive is sent before the first byte. 88/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Electrical characteristics USB characteristics The STM32F042x4/x6 USB interface is fully compliant with the USB specification version 2.0 and is USB-IF certified (for Full-speed device operation). Table 65. USB electrical characteristics Symbol Conditions Min. Typ Max. Unit USB transceiver operating voltage - 3.0(1) - 3.6 V tSTARTUP(2) USB transceiver startup time - - - 1.0 s RPUI Embedded USB_DP pull-up value during idle - 1.1 1.26 1.5 RPUR Embedded USB_DP pull-up value during reception - ZDRV(2) Output driver impedance(3) VDDIO2 Parameter k Driving high and low 2.0 2.26 2.6 28 40 44 1. The STM32F042x4/x6 USB functionality is ensured down to 2.7 V but not the full USB electrical characteristics which are degraded in the 2.7-to-3.0 V voltage range. 2. Guaranteed by design, not tested in production. 3. No external termination series resistors are required on USB_DP (D+) and USB_DM (D-); the matching impedance is already included in the embedded driver. CAN (controller area network) interface Refer to Section 6.3.14: I/O port characteristics for more details on the input/output alternate function characteristics (CAN_TX and CAN_RX). DocID025832 Rev 5 89/117 89 Package information 7 STM32F042x4 STM32F042x6 Package information In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK(R) packages, depending on their level of environmental compliance. ECOPACK(R) specifications, grade definitions and product status are available at: www.st.com. ECOPACK(R) is an ST trademark. 7.1 LQFP48 package information LQFP48 is a 48-pin, 7 x 7 mm low-profile quad flat package. Figure 33. LQFP48 package outline F $ $ $ 6($7,1* 3/$1( & PP *$8*(3/$1( FFF & . $ ' ' / / ' 3,1 ,'(17,),&$7,21 ( H 1. Drawing is not to scale. 90/117 ( ( E DocID025832 Rev 5 %B0(B9 STM32F042x4 STM32F042x6 Package information Table 66. LQFP48 package mechanical data inches(1) millimeters Symbol Min Typ Max Min Typ Max A - - 1.600 - - 0.0630 A1 0.050 - 0.150 0.0020 - 0.0059 A2 1.350 1.400 1.450 0.0531 0.0551 0.0571 b 0.170 0.220 0.270 0.0067 0.0087 0.0106 c 0.090 - 0.200 0.0035 - 0.0079 D 8.800 9.000 9.200 0.3465 0.3543 0.3622 D1 6.800 7.000 7.200 0.2677 0.2756 0.2835 D3 - 5.500 - - 0.2165 - E 8.800 9.000 9.200 0.3465 0.3543 0.3622 E1 6.800 7.000 7.200 0.2677 0.2756 0.2835 E3 - 5.500 - - 0.2165 - e - 0.500 - - 0.0197 - L 0.450 0.600 0.750 0.0177 0.0236 0.0295 L1 - 1.000 - - 0.0394 - k 0 3.5 7 0 3.5 7 ccc - - 0.080 - - 0.0031 1. Values in inches are converted from mm and rounded to 4 decimal digits. Figure 34. Recommended footprint for LQFP48 package DLG 1. Dimensions are expressed in millimeters. DocID025832 Rev 5 91/117 113 Package information STM32F042x4 STM32F042x6 Device marking The following figure gives an example of topside marking orientation versus pin 1 identifier location. Other optional marking or inset/upset marks, which identify the parts throughout supply chain operations, are not indicated below. Figure 35. LQFP48 package marking example 3URGXFWLGHQWLILFDWLRQ 670) &7 'DWHFRGH < :: 5HYLVLRQFRGH 5 06Y9 1. Parts marked as "ES", "E" or accompanied by an Engineering Sample notification letter, are not yet qualified and therefore not yet ready to be used in production and any consequences deriving from such usage will not be at ST charge. In no event, ST will be liable for any customer usage of these engineering samples in production. ST Quality has to be contacted prior to any decision to use these Engineering Samples to run qualification activity. 92/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 7.2 Package information UFQFPN48 package information UFQFPN48 is a 48-lead, 7x7 mm, 0.5 mm pitch, ultra-thin fine-pitch quad flat package. Figure 36. UFQFPN48 package outline 3LQLGHQWLILHU ODVHUPDUNLQJDUHD ' $ ( ( 7 GGG $ 6HDWLQJ SODQH E H 'HWDLO< ' ([SRVHGSDG DUHD < ' / &[ SLQFRUQHU ( 5W\S 'HWDLO= = $%B0(B9 1. Drawing is not to scale. 2. All leads/pads should also be soldered to the PCB to improve the lead/pad solder joint life. 3. There is an exposed die pad on the underside of the UFQFPN package. It is recommended to connect and solder this back-side pad to PCB ground. DocID025832 Rev 5 93/117 113 Package information STM32F042x4 STM32F042x6 Table 67. UFQFPN48 package mechanical data inches(1) millimeters Symbol Min Typ Max Min Typ Max A 0.500 0.550 0.600 0.0197 0.0217 0.0236 A1 0.000 0.020 0.050 0.0000 0.0008 0.0020 D 6.900 7.000 7.100 0.2717 0.2756 0.2795 E 6.900 7.000 7.100 0.2717 0.2756 0.2795 D2 5.500 5.600 5.700 0.2165 0.2205 0.2244 E2 5.500 5.600 5.700 0.2165 0.2205 0.2244 L 0.300 0.400 0.500 0.0118 0.0157 0.0197 T - 0.152 - - 0.0060 - b 0.200 0.250 0.300 0.0079 0.0098 0.0118 e - 0.500 - - 0.0197 - ddd - - 0.080 - - 0.0031 1. Values in inches are converted from mm and rounded to 4 decimal digits. Figure 37. Recommended footprint for UFQFPN48 package 1. Dimensions are expressed in millimeters. 94/117 DocID025832 Rev 5 $%B)3B9 STM32F042x4 STM32F042x6 Package information Device marking The following figure gives an example of topside marking orientation versus pin 1 identifier location. Other optional marking or inset/upset marks, which identify the parts throughout supply chain operations, are not indicated below. Figure 38. UFQFPN48 package marking example 3URGXFWLGHQWLILFDWLRQ 670) &8 'DWHFRGH < :: 5HYLVLRQFRGH 5 06Y9 1. Parts marked as "ES", "E" or accompanied by an Engineering Sample notification letter, are not yet qualified and therefore not yet ready to be used in production and any consequences deriving from such usage will not be at ST charge. In no event, ST will be liable for any customer usage of these engineering samples in production. ST Quality has to be contacted prior to any decision to use these Engineering Samples to run qualification activity. DocID025832 Rev 5 95/117 113 Package information 7.3 STM32F042x4 STM32F042x6 WLCSP36 package information WLCSP36 is a 36-ball, 2.605 x 2.703 mm, 0.4 mm pitch wafer-level chip-scale package. Figure 39. WLCSP36 package outline H EEE = $EDOOORFDWLRQ ) H * $ 'HWDLO$ H H ) $ $ $ %XPSVLGH 6LGHYLHZ ; < $ %XPS $ RULHQWDWLRQ UHIHUHQFH HHH = DDD = $ E EDOOV FFF = ; < GGG = :DIHUEDFNVLGH E = 6HDWLQJSODQH 'HWDLO$ URWDWHG >Ds 1. Drawing is not to scale. Table 68. WLCSP36 package mechanical data inches(1) millimeters Symbol Min Typ Max Min Typ Max A 0.525 0.555 0.585 0.0207 0.0219 0.0230 A1 - 0.175 - - 0.0069 - A2 - 0.380 - - 0.0150 - A3(2) - 0.025 - - 0.0010 - (3) 0.220 0.250 0.280 0.0087 0.0098 0.0110 D 2.570 2.605 2.640 0.1012 0.1026 0.1039 E 2.668 2.703 2.738 0.1050 0.1064 0.1078 e - 0.400 - - 0.0157 - e1 - 2.000 - - 0.0787 - e2 - 2.000 - - 0.0787 - b 96/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Package information Table 68. WLCSP36 package mechanical data (continued) inches(1) millimeters Symbol Min Typ Max Min Typ Max F - 0.3025 - - 0.0119 - G - 0.3515 - - 0.0138 - aaa - - 0.100 - - 0.0039 bbb - - 0.100 - - 0.0039 ccc - - 0.100 - - 0.0039 ddd - - 0.050 - - 0.0020 eee - - 0.050 - - 0.0020 1. Values in inches are converted from mm and rounded to 4 decimal digits. 2. Back side coating. 3. Dimension is measured at the maximum bump diameter parallel to primary datum Z. Figure 40. Recommended pad footprint for WLCSP36 package 'SDG 'VP 069 Table 69. WLCSP36 recommended PCB design rules Dimension Recommended values Pitch 0.4 mm Dpad 260 m max. (circular) 220 m recommended Dsm 300 m min. (for 260 m diameter pad) PCB pad design Non-solder mask defined via underbump allowed DocID025832 Rev 5 97/117 113 Package information STM32F042x4 STM32F042x6 Device marking The following figure gives an example of topside marking orientation versus ball A1 identifier location. Other optional marking or inset/upset marks, which identify the parts throughout supply chain operations, are not indicated below. Figure 41. WLCSP36 package marking example 'RW 3URGXFWLGHQWLILFDWLRQ )7 5HYLVLRQFRGH 5 'DWHFRGH < :: 06Y9 1. Parts marked as "ES", "E" or accompanied by an Engineering Sample notification letter, are not yet qualified and therefore not yet ready to be used in production and any consequences deriving from such usage will not be at ST charge. In no event, ST will be liable for any customer usage of these engineering samples in production. ST Quality has to be contacted prior to any decision to use these Engineering Samples to run qualification activity. 98/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 LQFP32 package information LQFP32 is a 32-pin, 7 x 7 mm low-profile quad flat package. Figure 42. LQFP32 package outline F $ $ $ 6($7,1* 3/$1( & PP FFF *$8*(3/$1( & . ' / $ ' / ' 3,1 ,'(17,),&$7,21 ( ( ( E 7.4 Package information H 7@.&@7 1. Drawing is not to scale. DocID025832 Rev 5 99/117 113 Package information STM32F042x4 STM32F042x6 Table 70. LQFP32 package mechanical data inches(1) millimeters Symbol Min Typ Max Min Typ Max A - - 1.600 - - 0.0630 A1 0.050 - 0.150 0.0020 - 0.0059 A2 1.350 1.400 1.450 0.0531 0.0551 0.0571 b 0.300 0.370 0.450 0.0118 0.0146 0.0177 c 0.090 - 0.200 0.0035 - 0.0079 D 8.800 9.000 9.200 0.3465 0.3543 0.3622 D1 6.800 7.000 7.200 0.2677 0.2756 0.2835 D3 - 5.600 - - 0.2205 - E 8.800 9.000 9.200 0.3465 0.3543 0.3622 E1 6.800 7.000 7.200 0.2677 0.2756 0.2835 E3 - 5.600 - - 0.2205 - e - 0.800 - - 0.0315 - L 0.450 0.600 0.750 0.0177 0.0236 0.0295 L1 - 1.000 - - 0.0394 - k 0 3.5 7 0 3.5 7 ccc - - 0.100 - - 0.0039 1. Values in inches are converted from mm and rounded to 4 decimal digits. Figure 43. Recommended footprint for LQFP32 package 1. Dimensions are expressed in millimeters. 100/117 DocID025832 Rev 5 9B)3B9 STM32F042x4 STM32F042x6 Package information Device marking The following figure gives an example of topside marking orientation versus pin 1 identifier location. Other optional marking or inset/upset marks, which identify the parts throughout supply chain operations, are not indicated below. Figure 44. LQFP32 package marking example 3URGXFWLGHQWLILFDWLRQ 670) .7 'DWHFRGH 3LQLGHQWLILFDWLRQ < :: 5HYLVLRQFRGH 5 06Y9 1. Parts marked as "ES", "E" or accompanied by an Engineering Sample notification letter, are not yet qualified and therefore not yet ready to be used in production and any consequences deriving from such usage will not be at ST charge. In no event, ST will be liable for any customer usage of these engineering samples in production. ST Quality has to be contacted prior to any decision to use these Engineering Samples to run qualification activity. 7.5 UFQFPN32 package information UFQFPN32 is a 32-pin, 5x5 mm, 0.5 mm pitch ultra-thin fine-pitch quad flat package. DocID025832 Rev 5 101/117 113 Package information STM32F042x4 STM32F042x6 Figure 45. UFQFPN32 package outline ' $ H $ $ ' GGG & & 6($7,1* 3/$1( E H ( E ( ( / 3,1,GHQWLILHU ' / $%B0(B9 1. Drawing is not to scale. 2. All leads/pads should also be soldered to the PCB to improve the lead/pad solder joint life. 3. There is an exposed die pad on the underside of the UFQFPN package. This pad is used for the device ground and must be connected. It is referred to as pin 0 in Table: Pin definitions. 102/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Package information Table 71. UFQFPN32 package mechanical data inches(1) millimeters Symbol Min Typ Max Min Typ Max A 0.500 0.550 0.600 0.0197 0.0217 0.0236 A1 0.000 0.020 0.050 0.0000 0.0008 0.0020 A3 - 0.152 - - 0.0060 - b 0.180 0.230 0.280 0.0071 0.0091 0.0110 D 4.900 5.000 5.100 0.1929 0.1969 0.2008 D1 3.400 3.500 3.600 0.1339 0.1378 0.1417 D2 3.400 3.500 3.600 0.1339 0.1378 0.1417 E 4.900 5.000 5.100 0.1929 0.1969 0.2008 E1 3.400 3.500 3.600 0.1339 0.1378 0.1417 E2 3.400 3.500 3.600 0.1339 0.1378 0.1417 e - 0.500 - - 0.0197 - L 0.300 0.400 0.500 0.0118 0.0157 0.0197 ddd - - 0.080 - - 0.0031 1. Values in inches are converted from mm and rounded to 4 decimal digits. Figure 46. Recommended footprint for UFQFPN32 package $%B)3B9 1. Dimensions are expressed in millimeters. DocID025832 Rev 5 103/117 113 Package information STM32F042x4 STM32F042x6 Device marking The following figure gives an example of topside marking orientation versus pin 1 identifier location. Other optional marking or inset/upset marks, which identify the parts throughout supply chain operations, are not indicated below. Figure 47. UFQFPN32 package marking example 3URGXFWLGHQWLILFDWLRQ ). 'DWHFRGH < :: 5HYLVLRQFRGH 5 'RW SLQ 06Y9 1. Parts marked as "ES", "E" or accompanied by an Engineering Sample notification letter, are not yet qualified and therefore not yet ready to be used in production and any consequences deriving from such usage will not be at ST charge. In no event, ST will be liable for any customer usage of these engineering samples in production. ST Quality has to be contacted prior to any decision to use these Engineering Samples to run qualification activity. 104/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 7.6 Package information UFQFPN28 package information UFQFPN28 is a 28-lead, 4x4 mm, 0.5 mm pitch, ultra-thin fine-pitch quad flat package. Figure 48. UFQFPN28 package outline 'HWDLO< ' ( ' ' ( 'HWDLO= $%B0(B9 1. Drawing is not to scale. Table 72. UFQFPN28 package mechanical data(1) millimeters inches Symbol Min Typ Max Min Typ Max A 0.500 0.550 0.600 0.0197 0.0217 0.0236 A1 - 0.000 0.050 - 0.0000 0.0020 D 3.900 4.000 4.100 0.1535 0.1575 0.1614 D1 2.900 3.000 3.100 0.1142 0.1181 0.1220 E 3.900 4.000 4.100 0.1535 0.1575 0.1614 E1 2.900 3.000 3.100 0.1142 0.1181 0.1220 L 0.300 0.400 0.500 0.0118 0.0157 0.0197 L1 0.250 0.350 0.450 0.0098 0.0138 0.0177 T - 0.152 - - 0.0060 - b 0.200 0.250 0.300 0.0079 0.0098 0.0118 e - 0.500 - - 0.0197 - DocID025832 Rev 5 105/117 113 Package information STM32F042x4 STM32F042x6 1. Values in inches are converted from mm and rounded to 4 decimal digits. Figure 49. Recommended footprint for UFQFPN28 package $%B)3B9 1. Dimensions are expressed in millimeters. 106/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Package information Device marking The following figure gives an example of topside marking orientation versus pin 1 identifier location. Other optional marking or inset/upset marks, which identify the parts throughout supply chain operations, are not indicated below. Figure 50. UFQFPN28 package marking example 3URGXFWLGHQWLILFDWLRQ )* 'DWHFRGH < :: 5 5HYLVLRQFRGH 'RW 06Y9 1. Parts marked as "ES", "E" or accompanied by an Engineering Sample notification letter, are not yet qualified and therefore not yet ready to be used in production and any consequences deriving from such usage will not be at ST charge. In no event, ST will be liable for any customer usage of these engineering samples in production. ST Quality has to be contacted prior to any decision to use these Engineering Samples to run qualification activity. DocID025832 Rev 5 107/117 113 Package information 7.7 STM32F042x4 STM32F042x6 TSSOP20 package information TSSOP20 is a 20-lead thin shrink small-outline, 6.5 x 4.4 mm, 0.65 mm pitch, package. Figure 51.TSSOP20 package outline ^d/E' W>E 'h'W>E W/E /Ed/&/d/KE > > zDs 1. Drawing is not to scale. Table 73. TSSOP20 package mechanical data inches(1) millimeters Symbol Min. Typ. Max. Min. Typ. Max. A - - 1.200 - - 0.0472 A1 0.050 - 0.150 0.0020 - 0.0059 A2 0.800 1.000 1.050 0.0315 0.0394 0.0413 b 0.190 - 0.300 0.0075 - 0.0118 c 0.090 - 0.200 0.0035 - 0.0079 (2) 6.400 6.500 6.600 0.2520 0.2559 0.2598 E 6.200 6.400 6.600 0.2441 0.2520 0.2598 E1(3) 4.300 4.400 4.500 0.1693 0.1732 0.1772 e - 0.650 - - 0.0256 - L 0.450 0.600 0.750 0.0177 0.0236 0.0295 D 108/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 Package information Table 73. TSSOP20 package mechanical data (continued) inches(1) millimeters Symbol Min. Typ. Max. Min. Typ. Max. L1 - 1.000 - - 0.0394 - k 0 - 8 0 - 8 aaa - - 0.100 - - 0.0039 1. Values in inches are converted from mm and rounded to four decimal digits. 2. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusions or gate burrs shall not exceed 0.15mm per side. 3. Dimension "E1" does not include interlead flash or protrusions. Interlead flash or protrusions shall not exceed 0.25mm per side. Figure 52. Recommended footprint for TSSOP20 package <$B)3B9 1. Dimensions are expressed in millimeters. DocID025832 Rev 5 109/117 113 Package information STM32F042x4 STM32F042x6 Device marking The following figure gives an example of topside marking orientation versus pin 1 identifier location. Other optional marking or inset/upset marks, which identify the parts throughout supply chain operations, are not indicated below. Figure 53. TSSOP20 package marking example 3URGXFWLGHQWLILFDWLRQ ))3 'DWHFRGH 3LQLGHQWLILHU < :: 5 5HYLVLRQFRGH 06Y9 1. Parts marked as "ES", "E" or accompanied by an Engineering Sample notification letter, are not yet qualified and therefore not yet ready to be used in production and any consequences deriving from such usage will not be at ST charge. In no event, ST will be liable for any customer usage of these engineering samples in production. ST Quality has to be contacted prior to any decision to use these Engineering Samples to run qualification activity. 110/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 7.8 Package information Thermal characteristics The maximum chip junction temperature (TJmax) must never exceed the values given in Table 21: General operating conditions. The maximum chip-junction temperature, TJ max, in degrees Celsius, may be calculated using the following equation: TJ max = TA max + (PD max x JA) Where: * TA max is the maximum ambient temperature in C, * JA is the package junction-to-ambient thermal resistance, in C/W, * PD max is the sum of PINT max and PI/O max (PD max = PINT max + PI/Omax), * PINT max is the product of IDD and VDD, expressed in Watts. This is the maximum chip internal power. PI/O max represents the maximum power dissipation on output pins where: PI/O max = (VOL x IOL) + ((VDDIOx - VOH) x IOH), taking into account the actual VOL / IOL and VOH / IOH of the I/Os at low and high level in the application. Table 74. Package thermal characteristics Symbol JA 7.8.1 Parameter Value Thermal resistance junction-ambient LQFP48 - 7 mm x 7 mm 55 Thermal resistance junction-ambient UFQFPN48 - 7 mm x 7 mm 33 Thermal resistance junction-ambient WLCSP36 2.6 mm x 2.7 mm 64 Thermal resistance junction-ambient LQFP32 - 7 mm x 7 mm 57 Thermal resistance junction-ambient UFQFPN32 - 5 mm x 5 mm 38 Thermal resistance junction-ambient UFQFPN28 - 4 mm x 4 mm 118 Thermal resistance junction-ambient TSSOP20 - 6.5 mm x 6.4 mm 76 Unit C/W Reference document JESD51-2 Integrated Circuits Thermal Test Method Environment Conditions - Natural Convection (Still Air). Available from www.jedec.org 7.8.2 Selecting the product temperature range When ordering the microcontroller, the temperature range is specified in the ordering information scheme shown in Section 8: Ordering information. DocID025832 Rev 5 111/117 113 Package information STM32F042x4 STM32F042x6 Each temperature range suffix corresponds to a specific guaranteed ambient temperature at maximum dissipation and, to a specific maximum junction temperature. As applications do not commonly use the STM32F042x4/x6 at maximum dissipation, it is useful to calculate the exact power consumption and junction temperature to determine which temperature range will be best suited to the application. The following examples show how to calculate the temperature range needed for a given application. 112/117 DocID025832 Rev 5 STM32F042x4 STM32F042x6 8 Ordering information Ordering information For a list of available options (memory, package, and so on) or for further information on any aspect of this device, please contact your nearest ST sales office. Table 75. Ordering information scheme STM32 F Example: 042 C 6 T 6 xxx Device family STM32 = ARM-based 32-bit microcontroller Product type F = General-purpose Sub-family 042 = STM32F042xx Pin count F = 20 pins G = 28 pins K = 32 pins T = 36 pins C = 48 pins User code memory size 4 = 16 Kbyte 6 = 32 Kbyte Package P = TSSOP T = LQFP U = UFQFPN Y = WLCSP Temperature range 6 = -40 to 85 C 7 = -40 to 105 C Options xxx = code ID of programmed parts (includes packing type) TR = tape and reel packing blank = tray packing DocID025832 Rev 5 113/117 113 Revision history 9 STM32F042x4 STM32F042x6 Revision history Table 76. Document revision history Date Revision 25-Feb-2014 1 Initial release. 2 Added the sample engineering sections for all the packages in the chapter Package information: Updated tables: - STM32F042x4/x6 USART implementation: added one table footnote. - STM32F042x pin definitions, - Current characteristics, - Typical and maximum current consumption from VDD supply at VDD = 3.6 V, - Typical and maximum current consumption from the VDDA supply, - Typical and maximum consumption in Stop and Standby modes, - Typical and maximum current consumption from the VBAT supply, - Typical current consumption, code executing from Flash, running from HSE 8 MHz crystal, - Flash memory characteristics, - I/O static characteristics, - I/O current injection susceptibility, - EMS characteristics, - EMI characteristics, Updated figures: - UFQFPN32 32-pin package pinout, - UQFPN28 28-pin package, - Power supply scheme, - TC and TTa I/O input characteristics, - Five volt tolerant (FT and FTf) I/O input characteristics. - LQFP48 marking example (package top view), - UFQFPN48 marking example (package top view), - WLCSP36 marking example (package top view), - LQFP32 marking example (package top view), - UFQFPN28 marking example (package top view), - UFQFPN32 marking example (package top view), - TSSOP20 marking example (package top view) 3 Cover page: number of I/Os and timers updated. Updates in Section 2: Description: - updated Figure 1: Block diagram Updates in Section 3: Functional overview: - updated Figure 2: Clock tree - addition of the number of complementary outputs for the advanced control timer and for TIM16, TIM17 general purpose timers in Table 7: Timer feature comparison - removal of USART2 from Figure 3.5.4: Low-power modes 03-Apr-2014 26-Oct-2015 114/117 Changes DocID025832 Rev 5 STM32F042x4 STM32F042x6 Revision history Table 76. Document revision history (continued) Date Revision Changes 2 26-Oct-2015 3 - Table 9: STM32F042x4/x6 I C implementation - adding 20 mA Updates in Section 4: Pinouts and pin descriptions - Table 12: Legend/abbreviations used in the pinout table - removing "I" pin type Updates in Section 5: Memory mapping: - Figure 10: STM32F042x6 memory map, x4 difference described in text Updates in Section 6: Electrical characteristics: - the condition "Regulator in run mode, all oscillators OFF" in Table 28: Typical and maximum consumption in Stop and Standby modes, - footnote for VIN max value in Table 18: Voltage characteristics, - footnote for max VIN in Table 21: General operating conditions, - tSTART parameter definition in Table 25: Embedded internal reference voltage - addition of tSTART parameter in Table 25: Embedded internal reference voltage, removal of -40C to 85C condition and the associated footnote - Table 26: Typical and maximum current consumption from VDD supply at VDD = 3.6 V: removing "code executing from Flash or RAM" - removal of the min value for tSTART parameter in Table 57: TS characteristics - the typical value for R parameter in Table 58: VBAT monitoring characteristics - removal of ResTM parameter line from Table 59: TIMx characteristics and putting all values in new Typ column, substitution of tCOUNTER with tMAX_COUNT, values defined as powers of two - VESD(CDM) class in Table 47: ESD absolute maximum ratings - reorganization of Table 64: I2S characteristics and filling max value of tv(SD_ST) - adding definition of levels in Figure 32: I2S master timing diagram (Philips protocol) Updates in Section 7: Package information: - heading and display of columns in Table 68: WLCSP36 package mechanical data., - Figure 38: UFQFPN48 package marking example - Figure 41: WLCSP36 package marking example - Figure 50: UFQFPN28 package marking example - Figure 41: WLCSP36 package marking example - Figure 51: TSSOP20 package outline - correcting GAGE to GAUGE - removing "die 445" from Table 74: Package thermal characteristics Updates in Section 8: Part numbering: - adding tray packing to options DocID025832 Rev 5 115/117 116 Revision history STM32F042x4 STM32F042x6 Table 76. Document revision history (continued) Date 16-Dec-2015 10-Jan-2017 116/117 Revision Changes 4 Section 3: Functional overview: - Figure 2: Clock tree modified Section 4: Pinouts and pin descriptions: - Package pinout figures updated (look and feel) - Figure 5: WLCSP36 package pinout- now presented in top view - Table 13: STM32F042x pin definitions - note 3 added; CIMP1_OUT and USART4_CTS removed - Table 15: Alternate functions selected through GPIOB_AFR registers for port B - change of I2C2_SDA and I2C2_SCL to I2C1_SDA and I2C1_SCL Section 5: Memory mapping: - Table 17: STM32F042x4/x6 peripheral register boundary addresses - change of "SYSCFG + COMP" to "SYSCFG" Section 6: Electrical characteristics: - Table 50: I/O static characteristics- removed note - Section 6.3.16: 12-bit ADC characteristics - changed introductory sentence Section 7: Package information: - Figure 49: Recommended footprint for UFQFPN28 package distance between corner pads added 5 Section 6: Electrical characteristics: - Table 37: LSE oscillator characteristics (fLSE = 32.768 kHz) information on configuring different drive capabilities removed. See the corresponding reference manual. - Table 25: Embedded internal reference voltage - VREFINT values - Figure 28: SPI timing diagram - slave mode and CPHA = 0 and Figure 29: SPI timing diagram - slave mode and CPHA = 1 enhanced and corrected Section 8: Ordering information: - The name of the section changed from the previous "Part numbering" DocID025832 Rev 5 STM32F042x4 STM32F042x6 IMPORTANT NOTICE - PLEASE READ CAREFULLY STMicroelectronics NV and its subsidiaries ("ST") reserve the right to make changes, corrections, enhancements, modifications, and improvements to ST products and/or to this document at any time without notice. Purchasers should obtain the latest relevant information on ST products before placing orders. ST products are sold pursuant to ST's terms and conditions of sale in place at the time of order acknowledgement. Purchasers are solely responsible for the choice, selection, and use of ST products and ST assumes no liability for application assistance or the design of Purchasers' products. No license, express or implied, to any intellectual property right is granted by ST herein. Resale of ST products with provisions different from the information set forth herein shall void any warranty granted by ST for such product. ST and the ST logo are trademarks of ST. All other product or service names are the property of their respective owners. Information in this document supersedes and replaces information previously supplied in any prior versions of this document. (c) 2017 STMicroelectronics - All rights reserved DocID025832 Rev 5 117/117 117