TIDUF29 October   2023

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
  8. 2System Overview
    1. 2.1 Block Diagram
    2. 2.2 Design Considerations
      1. 2.2.1 Connectors
      2. 2.2.2 High-Speed Traces
      3. 2.2.3 Power Rails
    3. 2.3 Highlighted Products
      1. 2.3.1 DS560DF410
      2. 2.3.2 TPS62867
      3. 2.3.3 TPS7A52
      4. 2.3.4 TLV702
      5. 2.3.5 TXB0108
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
      1. 3.1.1 TX Output Eye Test
      2. 3.1.2 RX Link Test
    2. 3.2 Software Requirements
    3. 3.3 Test Setup
      1. 3.3.1 TX Output Eye Test
      2. 3.3.2 RX Link Test
    4. 3.4 Test Results
      1. 3.4.1 TX Output Eye Test
      2. 3.4.2 RX Link Test
  10. 4Design and Documentation Support
    1. 4.1 Design Files
      1. 4.1.1 Schematics
      2. 4.1.2 BOM
      3. 4.1.3 Altium Project
    2. 4.2 Tools and Software
    3. 4.3 Documentation Support
    4. 4.4 Support Resources
    5. 4.5 Trademarks

3.3.2 RX Link Test

This procedure specifically explains how to measure the BER of 26.5625GBd PAM-4 PRBS31Q data passing through retimer U17 channel 2 on the first TIDA-060043 board, a passive QSFP cable, and retimer U15 channel 2 on the second TIDA-060043 board.

GUID-20230927-SS0I-HRMC-JJJH-R0HNVL4PDTHS-low.svg Figure 3-2 RX Link Test Setup
  1. Plug the passive QSFP cable into the QSFP-DD port on both TIDA-060043 boards (J27). Plug the MXP40 connector onto J19 of the first TIDA-060043 board.
  2. Using SMA cables, connect J19 pins 5, 6 on the first TIDA-060043 board to the BERT output.
  3. Connect the PC to the USB port on the first TIDA-060043 board (J2) using the USB2.0 mini cable.
  4. Connect the power supplies to the +3.3-V barrel jacks on both TIDA-060043 boards (J3) using the supply leads. Power both boards with 3.3 V.
  5. Configure the BERT to output 26.5625GBd PAM-4 PRBS31Q data.
  6. Open Latte on the PC and run setup.py. Make sure setupInfo = 0 and devIdentifier = 1.
  7. Run devinit.py. Make sure device.slaveAddr = 0x19 on line 79 as this address corresponds to retimer U17 on TIDA-060043.
  8. Configure 1_bringupParams.py for 26.5625GBd PAM-4 data enabled on Q0CH2. Run 1_bringupParams.py.
  9. Run 2_bringupLib.py. Run the "READBACK CHANNEL INIT STATUS / LOCK STATUS" code block of usefulFunctions.py and confirm channel 2 has CDR lock.
  10. Unplug the USB cable from the first TIDA-060043 board and plug the cable into the USB port of the second TIDA-060043 board (J2).
  11. Run setup.py. Make sure setupInfo = 0 and devIdentifier = 1.
  12. Run devinit.py. Make sure device.slaveAddr = 0x18 on line 79 as this address corresponds to retimer U15 on TIDA-060043.
  13. Configure 1_bringupParams.py for 26.5625GBd PAM-4 data enabled on Q0CH2. Make sure sysParams.rxPrbsSel = [x,x,5,x,…] so the device knows it is receiving PRBS31Q data on channel 2. Run 1_bringupParams.py.
  14. Run 2_bringupLib.py. Run the "READBACK CHANNEL INIT STATUS / LOCK STATUS" code block of usefulFunctions.py and confirm channel 2 has CDR lock.
  15. Run the "READBACK BER" code block of usefulFunction.py. Tune the FFE taps on the BERT to optimize the BER. For the results shown in Table 3-1, BERT FFE settings of pre1=-8 and post1=-5 were used.
  16. Run "READBACK BER" at least 3 times and record the resulting BER.