E-Tile Transceiver PHY User Guide

ID 683723
Date 4/01/2024
Document Table of Contents

9.2.21. 0x002B: RX Termination and TX Driver Tri-state Behavior

Attribute Code



Sets RX termination and TX driver tri-state behavior.

  • 0x84[0]: 1'b1: RX termination to VCCH_GXE
  • 0x84[1]: 1'b0: Active termination to ground/VCCH_GXE based on 0x84[0]
  • 0x84[1]: 1'b1: Termination undriven (floating)
  • 0x84[3:2]: 2'h0
  • 0x84[4]: 1'b0: Normal TX behavior (both TX outputs driven to VCCH_GXE) (default)
  • 0x84[4]: 1'b1: TX output tristated when disabled
  • 0x84[5]: 1'b0: Configure RX termination (0x84[4] is ignored)
  • 0x84[5]: 1'b1: Configure TX tri-state (0x84[1:0] are ignored)
  • 0x84[7:6]: 2'h0
  • 0x85[7:0]: 8'h00

When you use external AC-coupling capacitors, set RX termination to VCCH_GXE; whereas, when you do not use external AC-coupling caps, set RX termination to floating. The RX termination is floating after device configuration and after a PMA analog reset.

Table 78.  Configuring RX Termination and TX Tri-state
{0x89[7:0], 0x88[7:0]} {0x85[7:0],0x84[7:0]} Description
0x002B 0x0001 RX termination set to VCCH_GXE - TX tri-state behavior unchanged
0x002B 0x0002 RX termination set to float - TX tri-state behavior unchanged
0x002B 0x0020 Disable tri-state (default) - RX termination setting unchanged
0x002B 0x0030 Enable TX tristate - RX termination setting unchanged

PMA Can Be Running While Updating PMA Attribute?


Return Value {0x89[7:0],0x88[7:0]}