Triple-Speed Ethernet Intel® FPGA IP User Guide

ID 683402
Date 11/25/2022
Public

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

5.2.1. Control Register (Word Offset 0x00)

Table 48.  PCS Control Register Bit Descriptions
Bit(s) Name R/W Description
0:4 Reserved
5 UNIDIRECTIONAL_ENABLE RW Enables the unidirectional function. This bit depends on bit 12. When bit 12 is one, this bit is ignored.

When bit 12 is zero, bit 5 indicates the unidirectional function:

  • A value of 1 enables transmit from media independent interface regardless of whether the PHY has determined that a valid link has been established.
  • A value of 0 enables transmit from media independent interface only when the PHY has determined that a valid link has been established.

The reset value of this bit is zero.

6, 13 SPEED_SELECTION RO Indicates the operating mode of the PCS function. Bits 6 and 13 are set to 1 and 0 respectively. This combination of values represent the gigabit mode.

Bit [6, 13]:

  • 00: 10 Mbps
  • 01: 100 Mbps
  • 10: 1 Gigabit
  • 11: Reserved
7 COLLISION_TEST RO The 1000BASE-X PCS function does not support half-duplex mode. This bit is always set to 0.

Ignore this bit if you are using SGMII PCS function.

8 DUPLEX_MODE RO The 1000BASE-X PCS function only supports full-duplex mode. This bit is always set to 1.

Ignore this bit if you are using SGMII PCS function.

9 RESTART_AUTO_
NEGOTIATION RW Set this bit to 1 to restart the auto-negotiation sequence. For normal operation, set this bit to 0 (reset value).
10 ISOLATE RW Set this bit to 1 to isolate the PCS function from the MAC layer device. For normal operation, set this bit to 0 (reset value).
11 POWERDOWN RW Set this bit to 1 to power down the transceiver quad. The PCS function then asserts the powerdown signal to indicate the state it is in.
12 AUTO_NEGOTIATION_ENABLE RW Set this bit to 1 (reset value) to enable auto-negotiation.
14 LOOPBACK RW PHY loopback. Set this bit to 1 to implement loopback in the GX transceiver. For normal operation, set this bit to 0 (reset value). This bit is ignored if reduced ten-bit interface (RTBI) is implemented.

This feature is supported in all device families except the Cyclone IV GX device families.

15 RESET RW Self-clearing reset bit. Set this bit to 1 to generate a synchronous reset pulse which resets all the PCS function state machines, comma detection function, and 8b/10b encoder and decoder. For normal operation, set this bit to 0 (asynchronous reset value).