F-tile Architecture and PMA and FEC Direct PHY IP User Guide

ID 683872
Date 12/15/2021
Public

A newer version of this document is available.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

Document Table of Contents
Give Feedback

3.14.1.3. TX Equalizer Settings

The TX equalizer settings provides a way to tune your PMA TX buffer to optimize link performance.

To update the TX equalizer settings, follow these steps:

  1. Set csr_txffe_coeff_load (0x45080[0]) to 1’b0.
  2. Set TX equalizer co-efficients to valid settings:
    • TX equalizer pre-cursor 3 register csr_txffe_coeff_p5(0x45084[23:18]).
    • TX equalizer pre-cursor 2 register csr_txffe_coeff_m2(0x45080[7:2]).
    • TX equalizer pre-cursor 1 register csr_txffe_coeff_m1(0x45080[13:8]).
    • TX equalizer main cursor register csr_txffe_coeff_0(0x45080[20:14]).
    • TX equalizer post-cursor 1 register csr_txffe_coeff_p1(0x45080[26:21]).
    • TX equalizer post-cursor 2 register csr_txffe_coeff_p2(0x45084[5:0]).
    • TX equalizer post-cursor 3 register csr_txffe_coeff_p3(0x45084[11:6])
    • TX equalizer post-cursor 4 register csr_txffe_coeff_p4(0x45084[17:12]).
  3. Toggle csr_txffe_coeff_load (0x45080[0]) to 1’b1 and back to 1’b0.
    Note: For the range of TX PMA equalizer parameters, refer to .
    Table 85.  Main Cursor (C0) Real Co-efficient Values
    Main Cursor (C0) – Register 0x45080[20:14]

    Settings (decimal)

    Real Co-efficient Values
    0 0
    1 0.5
    2 1
    82 41
    83 41.5
    Table 86.  Pre-Cursor (C-1) and Post-Cursor (C1) Real Co-efficient Values

    Pre-Cursor (C-1) – Register 0x45080[13:8]

    Post-Cursor (C1) – Register 0x45080[26:21]

    Settings (decimal)

    Real Co-efficient Values
    0 0
    1 0.5
    2 1
    30 15
    31 15.5
    32 -16
    33 -15.5
    62 -1
    63 -0.5
    Table 87.  Pre-Cursor (C-2, C-3) and Post-Cursor (C2, C3, C4) Real Co-efficient Values

    Pre-Cursor (C-2) – Register 0x45080 [7:2]

    Pre-Cursor (C-3) – Register 0x45084[23:18]

    Post-Cursor (C2) – Register 0x45084[5:0]

    Post-Cursor (C3) – Register 0x45084[11:6]

    Post-Cursor (C4) – Register 0x45084[17:12]

    Settings (decimal)

    Real Co-efficient Values
    0 0
    1 0.25
    2 0.5
    30 7.5
    31 7.75
    32 -8
    33 -7.75
    62 -0.5
    63 -0.25