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

2.4.3 Example: Programming DS560DF410EVM for 26.5625 GBd PAM4 Test Case

In this step, the retimer device on the DS560DF410EVM is programmed. See the procedure that follows:

  1. Provide a valid input signal to the DUT retimer channel.
  2. Execute setup.py (user can select file on side panel and click F5).
  3. Execute devinit.py (user can select file on side panel and click F5).

  4. Execute 1_bringupParams.py after entering the desired 26.5625 GBd retimer settings for the Bringup Parameters, as shown in Figure 2-5.

    • Data rate is entered in unit of GBd.
    • PAM4 mode is enabled by setting system variable to 1.
    • For this case, PRBS31Q pattern is selected for Tx and Rx PRBS functions through value of 5.
    GUID-20221103-SS0I-RPSC-ZT0V-JKBBBH8PT55B-low.pngFigure 2-5 Latte GUI Snapshot Showing the User Configurable Retimer Parameters from the 1_bringupParams.py Script
  5. Execute the 2_bringupLib.py script. This script will load and apply a ROM patch before initializing all enabled retimer channels, as shown in Figure 2-6.
    Note: At the end of the bring-up scripts, the variables quad and ch will be set corresponding to the last retimer channel enabled. The variables can be re-assigned according to the channel of interest by manually entering values in one of the Latte scripts.
    GUID-20221103-SS0I-XMCP-8RWR-C8GJDCVRSDDP-low.png Figure 2-6 Example Latte GUI Log Window Snapshot Showing ROM Patch Load and Channel Initialization
  6. If the retimer channel in question is intended to serve as Tx PRBS generator for retimer Tx to retimer Rx link tests, then the usefulFunctions.py script can be used to configure this channel accordingly, as shown in Figure 2-7.
    • Go to Configure transmitter section of usefulFunctions.py.
    • Set parameter mode = 2 for transmit PRBS pattern.
    • Set the numeric value for the pattern variable for the desired pattern.
    • The user can highlight the configure transmitter command lines on the Latte window and click on F7 to execute only those commands.
    GUID-20230202-SS0I-BMST-8RHV-GJRNLMBCGZCT-low.png Figure 2-7 Latte GUI Snapshot Showing the usefulFunctions.py User Parameters