GTS Transceiver PHY User Guide

ID 817660
Date 4/01/2024
Public

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Document Table of Contents

3.13.1.1. Direct Register Method Examples

The following examples demonstrate the direct register method to configure the GTS PMA.

TX Equalizer Co-efficients

To set the TX equalizer co-efficients:
  • Write the TX equalizer pre_tap_2 register (0x97830[18:16]) with valid value.
  • Write the TX equalizer pre_tap_1 register (0x97830[9:5]) with valid value.
  • Write the TX equalizer main_tap register (0x97830[15:10]) with valid value.
  • Write the TX equalizer post_tap_1 register (0x97830[4:0]) with valid value.

Mute TX Output

To mute TX output (to configure TX output to 0 V):
  • Set 0x91750[25:24] to 2’b11
To unmute TX output:
  • Set 0x91750[25:24] to 2’b00

Internal Serial Loopback

To enable internal serial loopback:

Step 1:
  • Set 0x91418[31] to 0x0
Step 2:
  • Set 0x91420[25] to 0x1
  • Set 0x91418[29] to 0x1
Step 3:
  • Set 0x91418[31] to 0x1

To disable internal serial loopback:

Step 1:
  • Set 0x91418[31] to 0x0
Step 2:
  • Set 0x91418[29] to 0x0
  • Set 0x91420[25] to 0x0

TX to RX Parallel Loopback

To enable the TX to RX Parallel Loopback:
  • Write 0x1 to 0x916A4[8]
To disable the TX to RX Parallel Loopback:
  • Write 0x0 to 0x916A4[8]

Polarity Inversion

For TX polarity inversion:
  • Assert TX reset.
  • TX polarity inversion:
    • Write 0x1 to 0x91428[7]
  • TX polarity inversion revert back:
    • Write 0x0 to 0x91428[7]
  • Deassert TX reset.
For RX polarity inversion:
  • Assert RX reset.
  • RX polarity inversion:
    • Write 0x1 to 0x91428[6]
  • RX polarity inversion revert back:
    • Write 0x0 to 0x91428[6]
  • Deassert RX reset.
The sequence is valid only when RX manual tuning is used (bypass RX auto adaptation). If RX auto adaptation is used, use the GTS attribute access method.