Cyclone® V Avalon® Streaming (Avalon-ST) Interface for PCIe* Solutions User Guide

ID 683524
Date 6/02/2020
Public
Document Table of Contents

15.7.4. Disabling the Scrambler for Gen1 and Gen2 Simulations

The encoding scheme implemented by the scrambler applies a binary polynomial to the data stream to ensure enough data transitions between 0 and 1 to prevent clock drift. The data is decoded at the other end of the link by running the inverse polynomial.

Complete the following steps to disable the scrambler:

  1. Open <work_dir>/ <variant>/testbench/<variant>_tb/simulation/submodules/altpcie_tbed_<dev>_hwtcl.v.
  2. Search for the string, test_in.
  3. To disable the scrambler, set test_in[2] = 1.
  4. Save altpcie_tbed_sv_hwtcl.v.