GTS Ethernet Intel® FPGA Hard IP User Guide

ID 817676
Date 8/05/2024
Public
Document Table of Contents

11.1.1. Internal Serial Loopback

The output of the TX PMA is connected to the input of the RX PMA, forming a loopback connection.
Figure 70. Internal Serial Loopback

Follow these steps to enable Serial Internal Loopback:

  1. Write 0x4 to the soft_rx_rst(0x108) register to assert the soft RX reset.
  2. Write 0x6A340 to address 0xA403C.
  3. Poll address 0xA4040 until bit 14 = 0 and bit 15 = 1.
  4. Write 0x62340 to address 0xA403C.
  5. Poll address 0xA4040 until bit 14 = 0 and bit 15 = 0.
  6. De-assert RX reset by writing 0x0 to 0x108 register.

Enabling Serial Internal Loopback in Design Example

The design example support both internal serial loopback and external loopback modes. To enable Serial internal loopback, in system console execute run_test.