25G Ethernet Intel® Arria® 10 FPGA IP User Guide

ID 683639
Date 3/29/2021
Document Table of Contents

5. Reset

Control and Status registers control three parallel soft resets. These soft resets are not self-clearing. Software clears them by writing to the appropriate register. Asserting the external hard reset csr_rst_n returns Control and Status registers to their original values.
Figure 26. Conceptual Overview of Reset LogicThe three hard resets are top-level ports. The soft resets are internal signals which are outputs of the PHY_CONFIG register. Software writes the appropriate bit of the PHY_CONFIG to assert a soft reset.

The internal soft reset signals reset the following functions:

  • soft_txp_rst: Resets the IP core in TX direction. Resets the TX PCS, MAC, and adapter.This soft reset leads to deassertion of tx_lanes_stable output signal.
  • soft_rxp_rst: Resets the IP core in RX direction. Resets the RX PCS, MAC, and adapter. This soft reset leads to the deassertion of rx_pcs_ready output signal.
  • eio_sys_rst: Resets the IP core. Resets the TX and RX MACs, PCS, adapters, and transceivers. Does not reset the Control and Status registers. This soft reset leads to the deassertion of tx_lanes_stable and rx_pcs_ready output signal.