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

3.3.1 TX Output Eye Test

This procedure specifically explains how to measure a TX output eye of 26.5625GBd PAM-4 PRBS13Q data passing through retimer U15 channel 2 on the TIDA-060043 MCB board.

GUID-20230927-SS0I-BQJC-KHDF-NGG87WXKQ70Q-low.svg Figure 3-1 TX Output Eye Test Setup
  1. Plug the HCB breakout board into the QSFP-DD port on TIDA-060043 (J27). Plug MXP40 connectors onto J11 of TIDA-060043 and the port on the HCB labeled for RX signals.
  2. Using SMA cables, connect RX channel 2 of the HCB to the BERT output and J11 pins 3, 4 on TIDA-060043 to the DCA-X sampling oscilloscope input.
  3. Connect the PC to the USB port on TIDA-060043 (J2) using the USB2.0 mini cable.
  4. Connect the power supply to the +3.3-V barrel jack on TIDA-060043 (J3) using the supply lead. Power the board with 3.3 V.
  5. Configure the BERT to output 26.5625GBd PAM-4 PRBS13Q 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 = 0x18 on line 79 as this address corresponds to retimer U15 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. Configure the DCA-X to lock to 26.5625GBD PAM-4 PRBS13Q data and display the output eye.
  11. Using the "CHANGE TX-FFE" code block of usefulFunctions.py, tune the FFE taps while visually inspecting the output eye to optimize performance. For the results shown in Figure 3-3, settings of pre=2 and post=4 were used.
  12. Capture the eye diagram and jitter results on the DCA-X.