Low Latency 100G Ethernet Intel® FPGA IP Core User Guide: For Stratix® 10 Devices

ID 683100
Date 8/05/2024
Public
Document Table of Contents

7.8.28. Link Training Frame Contents for Lane 2

Provides CSRs for the following fields that are transmitted during link training to the link partner for Lane 2
  • TX EQ Coefficient Request to Link Partner on Lane 2
  • INIT Coefficients command to Link Partner on Lane 2
  • PRESET Coefficients command to Link Partner on Lane 2
  • Local TX EQ Coefficient Status for Lane 2
  • Local Receiver Ready Status for Lane 2
  • Most Recent TX EQ Coefficient Request from Link Partner on Lane 2
  • Most Recent INIT command from Link Partner on Lane 2
  • Most Recent PRESET command from Link Partner on Lane 2
  • Most Recent TX EQ Status from Link Partner on Lane 2
  • Most Recent Receiver Ready Status from Link Partner on Lane 2

Offset: 0xE5

Access: RO and RW

Link Training Frame Contents for Lane 2 Fields

Bit Name Description Access Reset
30 lp_receiver_ready_ln2 Link Partner Receiver Ready Status for Lane 2

1: The link partner receiver has determined that training is complete and is prepared to receive data

0: The link partner receiver is requesting that training continue

RO 0x0
29:24 lp_coefficient_status_ln2 TX EQ Coefficient Status from Link Partner for Lane 2

[5:4] Status of Link Partner (+1) TX EQ Coefficient

[3:2] Status of Link Partner (0) TX EQ Coefficient

[1:0] Status of Link Partner (-1) TX EQ Coefficient

The Coefficient values are encoded as follows:
  • 2'b00: Hold
  • 2'b01: Increment
  • 2'b10: Decrement
  • 2'b11: Reserved
RO 0x0
23 lp_preset_coefficients_ln2 PRESET Command from Link Partner on Lane 2

1: Set local TX EQ to PRESET

0: Normal Operation

This Field is normally Read-only, and the values are normally controlled by the Remote Partner Link Training SM.

When ovride_local_coef_enable=1, this field becomes writable, and is used to set the local values.

When ovride_local_coef_enable=1, use updated_local_coef_ln2=1 to write the local values.

RW 0x0
22 lp_initialize_coefficients_ln2 INIT Command from Link Partner on Lane 2

1: Set local TX EQ to INIT

0: Normal Operation

This Field is normally Read-only, and the values are normally controlled by the Remote Partner Link Training SM.

When ovride_local_coef_enable=1, this field becomes writable, and is used to set the local values.

When ovride_local_coef_enable=1, use updated_local_coef_ln2=1 to write the local values.

RW 0x0
21:16 lp_coefficient_update_ln2 TX EQ Coefficient Request from Link Partner on Lane 2

[5:4] Control for Local (+1) TX EQ Coefficient

[3:2] Control for Local (0) TX EQ Coefficient

[1:0] Control for Local (-1) TX EQ Coefficient

This Field is normally Read-only, and the values are normally controlled by the Remote Partner Link Training SM.

When ovride_local_coef_enable=1, this Field becomes writable, and is used to set the local values.

When ovride_local_coef_enable=1, use updated_local_coef_ln2=1 to write the local values.

The Coefficient values are encoded as follows:
  • 2'b00: Hold
  • 2'b01: Increment
  • 2'b10: Decrement
  • 2'b11: Reserved
RW 0x0
14 ld_receiver_ready_ln2 Local Receiver Ready Status for Lane 2

1: The local device receiver has determined that training is complete and is prepared to receive data

0: The local device receiver is requesting that training continue

RO 0x0
13:8 ld_coefficient_status_ln2 Local TX EQ Coefficient Status for Lane 2

[5:4] Status of Local (+1) TX EQ Coefficient

[3:2] Status of Local (0) TX EQ Coefficient

[1:0] Status of Local (-1) TX EQ Coefficient

The Coefficient values are encoded as follows:
  • 2'b00: Hold
  • 2'b01: Increment
  • 2'b10: Decrement
  • 2'b11: Reserved
RO 0x0
7 ld_preset_coefficients_ln2 PRESET Coefficients command to Link Partner on Lane 2

1: PRESET Coefficients

0: Normal Operation

This Field is normally Read-only, and the values are normally controlled by the Link Training SM.

When ovride_lp_coef_enable=1, this field becomes writable, and is used to set the values sent to the Link Partner.

When ovride_lp_coef_enable=1, useupdated_lp_coef_ln2=1 to transmit the values to the Link Partner.

The PRESET command is defined in IEEE 802.3 CL72.6.10.2.3.1.

RW 0x0
6 ld_initialize_coefficients_ln2 INIT Coefficients command to Link Partner on Lane 2

1: INIT Coefficients

0: Normal Operation

This field is normally Read-only, and the values are normally controlled by the Link Training SM.

When ovride_lp_coef_enable=1, this field becomes writable, and is used to set the values sent to the Link Partner.

When ovride_lp_coef_enable=1, useupdated_lp_coef_ln2=1 to transmit the values to the Link Partner.

The INIT command is defined in IEEE 802.3 CL72.6.10.2.3.2.

RW 0x0
5:0 ld_coefficient_update_ln2 TX EQ Coefficient Request to Link Partner on Lane 2

[5:4] Control for Link Partner (+1) TX EQ Coefficient

[3:2] Control for Link Partner (0) TX EQ Coefficient

[1:0] Control for Link Partner (-1) TX EQ Coefficient

This field is normally Read-only, and the values are normally controlled by the Link Training SM.

When ovride_lp_coef_enable=1, this field becomes writable, and is used to set the values sent to the Link Partner.

When ovride_lp_coef_enable=1, use updated_lp_coef_ln2=1 to transmit the values to the Link Partner.

The Coefficient values are encoded as follows:
  • 2'b00: Hold
  • 2'b01: Increment
  • 2'b10: Decrement
  • 2'b11: Reserved
RW 0x0