APPLICATION NOTE ISG-AN-01 ISG3300 EVAL BOARD USER GUIDE MANUAL Version 1.05 INTRODUCTION The ISG3300 EVAL Board is a fully implemented physical layer circuit board used for cable modem applications. It contains the ISG3300 cable transceiver, connectors to evaluate the RF characteristics of the transceiver, modulator and demodulator chips, ESD protection on the supply lines, and requires one dual power supply. CONNECTIONS The supply voltages required are 5 and 24 Volts DC. Apply 5 V with Digital Ground to the Power Header (see Diagram 2a). Apply 24 V with Analog Ground to the next pins. Each supply's negative terminal (analog and digital ground) should be connected together at the power supply and not on the board. The parallel port on PC1 connects to the dB 25 connector (refer to Diagrams 1 & 3). Lastly, the I2C interface board connects to PC2's parallel port and its I2C socket connects to the I2C header on the ISG3300 EVAL Board (refer to Diagram 3 or 4). In cases where the ISG3300 EVAL Board has a 18X1 connector (see Diagram 2a), the user is advised to plug the ISG3300 into the header before turning on the power supplies. Note that pins 1 and 18 are filled and keyed to minimize misalignments. Note: 1. The I2C board is not included. It may be ordered from Broadcom. RF Input/Output TxEn Tx_AGC Tx+ Tx- Modulator CLK LD_EN DATA Parallel Connector I2C IF+ IF- RF_AGC IF_AGC Demodulator Rx F-Connector Tx F-Connector ISG3300 Transceiver I2C Diagram 1: Block Diagram of ISG3300 Eval Board. 05/15/2000 Diagram 2a: Top side of EVAL Board. Diagram 2b: Underside of EVAL Board. Modulator: Bypassing Mod/Demod Chips The Broadcom BCM3037 I2C lines are connected at the bottom left 4-pin Tx header (see Diagram 2). This chip feeds a modulated QPSK/16-QAM signal and TX_AGC into the ISG3300. Apply 5 volts at the "5 V for Modulator" post (see diagram 2a) before running the software. To observe the RF characteristics of the ISG3300 EVAL Board, a few modifications are required. Refer to Diagrams 2a and 2b for locations. Applying external Tx Frequency 1. Remove R54 and R55. 2. Place R54B and R55B with 0-Ohm resistors. 3. Feed signal into Tx_In F-Connector. Demodulator: The bottom right 4-pin RX header (see Diagram 2) provides I2C lines to the BCM3116. This chip controls the two AGC lines on the receiver and demodulates recovered 5.75 MHz at QAM-64 or QAM-256 signals. Apply 5 volts at the "5 V for Demodulator" post (see diagram 2a) before running the software. Spectrum Analyzer Applying external TX_AGC 1. Remove R29. 2. Apply desired voltage at Tx _AGC (do not exceed 3.3 volts). 3. Remove R13. 4. Apply 3.3 volts at Tx_EN to turn on the TX circuitry. +58 to +8 dBmV QAM output PC1 w/ISG2K software ISG3300 EVAL BOARD 5V Power Supplies 24 V PC2 w/ Modulator software PC1 w/ISG2K software 12C Interface Board * Eval board to be powered on before starting modulator software. Diagram 3: Test Setup for Transmitter Evaluation Upconverter +15 to -15 dBmV QAM input ISG3300 EVAL BOARD Power Supplies QAM generator PC2 w/ Demodulator software 5V 24 V PC1 w/ISG2K software 12C Interface Board * Eval board to be powered on before starting modulator software. Diagram 4: Test Setup for Receiver Evaluation Applying External Rx AGCs 1. Remove R27 and R74. 3. Apply desired voltage to IF_AGC (do not exceed 3.3 volts). 4. Apply desired voltage to RF_AGC (do not exceed 3.3 volts). Screen to give the transmitter status. It is the screen that allows the user to modify parameters like frequency, symbol rate, amplitude level from the modulator (int power level), and TX_AGC (ext power level). Viewing Recovered 5.75 MHz IF_output. 1. Remove R51 and R53 (see Diagram 2b, underside). 2. Apply R50 and R52 with 0-Ohm resistors. 3. Connector Rx_Out F-connector to spectrum analyzer to view output. BCM93160.exe (or BCM93180.exe) This program sends commands to the BCM3116 (BCM3118) demodulator chip to recover QAM64 or QAM256 data. It has options to observe characteristics such as constellations, S/N ratio, and pre/ post BER. The program is set up to receive QAM64 with 5 MHz symbol rate, and Digicipher IITM FEC mode (BCM93180.exe needs DVB FEC mode). BROADCOM SOFTWARE Whether the ISG3300 EVAL BOARD is modulating or demodulating data, both cases require the board to be powered ON before starting the Broadcom programs. For further detail regarding the Broadcom software, refer to their Technical Information for BCM93160/BCM93037. BCM93037.exe The program will send commands to the 3037 to generate the desired QAM output for the return path. The software also allows the user to modify such parameters as Tx Freq, symbol rate, and power output (from the chip and from the ISG3300 transmitter). The following steps will get the user started to generate a QAM signal. 1. Run the BCM3037.exe executable program. 2. Upon initialization, the main menu for the UPSTRM Controller will appear. (If "Failed to Communicate w/ BCM3037" appears, check that header is connected correctly or check that X1 crystal is operating). 3. The lower right-hand corner gives status of connection to BCM3037. It should read I2C_COM_OK (I2C_NOACK indicates broken connection). 4. Hit F1: Run Command file 5. A list of files will appear. 6. Select QPSK and hit <ENTER>. 7. The main menu screen re-appears. The right hand side shows the 3037 should be transmitting a 2.56MHz symbol rate, QPSK signal, centered at 15MHz. Modifications to QAM Signal At the Main Menu, hit F3: Transmit Control The following steps will get the user started in recovering a QAM64 signal: 1. Run the BCM93160.exe (BCM93180.exe) executable program. 2. The main menu for QAMLink Controller will appear. 3. It should show Error Stat: NO ERROR to confirm the connection is good to the BCM3116. (I2C_NOACK will appear if there are problems). 4. If communication is good, but the QAM is: Out of Lock, then hit F1: Reacquire QAM Channel. The QAM is: In Lock will appear if data is recovered. 5. Depending on input RF levels, the SNR Est: is typically 30 to 36 dB. To view constellation, follow the following steps: 1. Hit F8: Monitor Constellation. 2. The screen shows a constellation on the left and bit-error-rate (BER), SNR statistics on the right. 3. On occasions, jumping into the constellation screen causes the 3116 to loose track of the QAM. Press F9: Require to recover the signal. To change to QAM 256 or Symbol Rate: 1. Hit F3: Select Acq Script. 2. Find the "256" Script. 3. Enter "1" for # of Attempts. 4. Enter "1000" for Wait Time. 5. Press <Enter> a few times to return to the Main Menu. 6. Hit F4: Set Symbol Rate. 7. Enter the symbol rate as displayed on QAM Generator. ISG SOFTWARE (Channel Selection) ISG has a software interface program, ISG2000 Demonstration Program, that will program both necessary VCOs frequencies on the ISG3300 to recover the desired input channel. 1. Run the ISG2K_12B.exe executable program. 2. A Windows-based user interface will appear. 3. Select the desire receiver channel in the R.F. Freq. box. If the frequency is not there, select a smaller Step Size, and select Increment or Decrement. 4. Press Reload to send commands to ISG3300. After the initial Reload, selecting Increment or Decrement (in units selected in Step Size box) will change the LOs to receive the next channels. Diagram 5: Recommended Pad Layout ISG BROADBAND, Inc. 4701 Patrick Henry Drive * SUITE #701 * Santa Clara, CA 95054-1863 * (408) 330-6660 FAX (408) 330-6688 * www.isgbroadband.com DATA SUBJECT TO CHANGE WITHOUT NOTICE 05/15/2000