E-tile Hard IP User Guide: E-Tile Hard IP for Ethernet and E-Tile CPRI PHY Intel® FPGA IPs

ID 683468
Date 12/13/2021
Public

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Document Table of Contents

2.12.1.18. Link Training Config Register 1

Offset: 0xD0

Link Training Config Register 1 Fields

Set bits [19:17] to 1 for internal loopback (ILB) or very short connections to disable LT optimizations.
Bit Name Description Access Reset
31:28 lt_cfg1_ovrd_bw CTLE-BW Override

When train_start_initpre set to 1, use this value for serdes CTLE-BW initial setting.

RW 0x0
27:24 lt_cfg1_ovrd_hf CTLE-HF Override

When train_start_initpre set to 1, use this value for serdes CTLE-HF initial setting.

RW 0x0
23:20 lt_cfg1_ovrd_lf CTLE-LF Override

When train_start_initpre set to 1, use this value for serdes CTLE-LF initial setting.

RW 0x0
19 lt_cfg1_disable_postlt Disables Post-LT optimized serdes settings

1: Disables optimizing serdes settings for KR post-LT and use default settings.

May be required for internal loopback (ILB) or very short connections.

RW 0x0
18 lt_cfg1_disable_prelt Disables Pre-LT optimized serdes settings

1: Disables optimizing serdes settings for KR pre-LT and use default settings.

May be required for internal loopback (ILB) or very short connections.

RW 0x0
17 lt_cfg1_disable_prxcal Disables Periodic RX Adaptation during Data Mode

1: Disables Periodic RX Adaptation during Data Mode

May be required for internal loopback (ILB) or very short connections

RW 0x0
16 lt_cfg1_disable_rxcal Disables Initial RX Adaptation during LT

1: Disables Initial RX Adaptation during LT

RW 0x0
15:4 lt_mw_time Sets LT Max_wait_timer timeout value

Each step is ~419.4us for NRZ, 2516.4us for PAM4.

Default value is 1192, or ~500ms for NRZ, ~3s for PAM4.

RW 12'h4a8
3 train_start_initpre Enable serdes initial RX setting override

1: Override initial serdes RX settings via 0xD0[31:20]

0: Use default serdes RX settings for Link Training (default)

Pre-LT optimized settings must be enabled for this to take effect (0xD0[18]==0)

RW 0x0
2 high_effort_train Use high-effort training

1: LT will use higher effort for RX train (may take more than 500ms)

0: LT will use standard effort for RX train (500ms)

RW 0x0
1 dis_max_wait_tmr Disable Max Wait Timer

1: Disable Max Wait Timer

0: Use Max Wait Timer (default)

RW 0x0
0 enable_link_training Enable Link Training

1: Enable link training

0: Disable link training

RW 0x1