SNLU324 March   2023

 

  1.   Abstract
  2.   Trademarks
  3. 1Hardware Description and Setup
    1. 1.1 Required Hardware
    2. 1.2 General Hardware Test Setup Procedure
    3. 1.3 Hardware Configuration to Use External 25 MHz Oscillator for CAL_CLK_IN
  4. 2Software Description
    1. 2.1 Software Installation Sequence
    2. 2.2 Latte Functional Overview
    3. 2.3 Useful Latte Short-Cuts
    4. 2.4 DS560DF410EVM Initialization Through the Latte GUI
      1. 2.4.1 Connect Latte to Board
      2. 2.4.2 Compile Libraries
      3. 2.4.3 Example: Programming DS560DF410EVM for 26.5625 GBd PAM4 Test Case
      4. 2.4.4 Retimer Configuration
      5. 2.4.5 Retimer Useful Functions (Contained in the usefulFunctions.py Latte Script)
      6. 2.4.6 Vertical Eye Monitor
  5. 3Related Documentation
    1. 3.1 Supplemental Content
  6. 4EVM Cable Assemblies

2.4.4 Retimer Configuration

The example in the previous section configures the DS560DF410EVM with the default modes set in Latte. The user can change the mode and channel by modifying the parameters in the 1_bringupParams.py Latte script.

  • Data rate: Data rate can be configured using system variable channelsDataRate. It is recommended to reset the device with this change.
  • Channel selection and initialization: Channels to be initialized can be selected using the system variable channelsEnabled array. Enable a specific retimer channel by setting the bit corresponding to it in the array (where channel order is sequential, from 0 to 7) to 1.
  • PAM4 / NRZ mode: Change the system variable pam4Mode, to switch between PAM4 and NRZ modes. A reset of the device is recommended once the mode is changed.

  • PRBS generator / checker polarity: To change the polarity of Tx PRBS generator, use variable txPolarityInv. To change the polarity of Rx PRBS checker, use variable rxPolarityInv.

  • PRBS selection: The PRBS pattern can be set through system variables rxPrbsSel and txPrbsSel. Enter the number corresponding to the desired pattern.
  • Channel type: The channel type can be selected with system variable channelType. Set this variable to 1 for use with a DAC cable or 0 for default mode.