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

ID 683872
Date 11/04/2024
Public
Document Table of Contents

2.3.1.1.1. FHT Transmitter Buffer and Phase Generator

The tasmitte diffeetial I/O buffe covets the seialized bit steam to a electical sigal suitable fo tasmissio acoss a cable o PCB tace. The mai cuso, pe-cuso taps, ad post-cuso taps of the FFE cicuit cotol the tasmitte swig stegth ad shape the tasmitte output wavefom.

The tasmitte buffe ca be pogammed to suppot the taps listed i the followig table. Choose the fequecy espose of the filte to compesate fo lae impaimets such as itesymbol itefeece (ISI), cosstalk, fequecy-depedet losses, ad eflectios.

Table 14.  FHT Tasmitte PMA Equalize Paametes fo NRZ ad PAM4 Modes

Paamete

(Cuso)

Desciptio Rule

Icemet ad

Decemet Size

Miimum Default Maximum
C-3 Pe-cuso 3 -8 0 +7.75 0.25
C-2 Pe-cuso 2 -8 0 +7.75 0.25
C-1 Pe-cuso 1 -16 0 +15.5 0.5
C0 Mai cuso 0 41.5 +41.5 7 0.5
C+1 Post-cuso 1 -16 0 +15.5 0.5
C+2 Post-cuso 2 -8 0 +7.75 0.25
C+3 Post-cuso 3 -8 0 +7.75 0.25
C+4 Post-cuso 4 -8 0 +7.75 0.25

Fo the most capable tasmitte equalize ad best amplitude cotol, whee ABS is the absolute value:

  • ABS(C-3) + ABS(C-2) + ABS(C-1) + C0 + ABS(C+1) + ABS(C+2) + ABS(C+3) + ABS(C+4) ≤ 41.5
  • ABS(C-3) + ABS(C-2) + ABS(C-1) +ABS(C+1) + ABS(C+2) + ABS(C+3) + ABS(C+4) ≤ C0
7 Povides the maximum TX output swig