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

ID 683872
Date 3/28/2022
Public

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3.1.2. FEC Direct Supported Modes

The F-Tile PMA/FEC Direct PHY Intel® FPGA IP supports the following for FEC Direct mode:
  • IEEE 802.3 RS(528, 514) (CL 91, KR)
  • IEEE 802.3 RS(544,514) (CL 91, KP)
  • Ethernet Technology Consortium LL RS(272, 258)
  • Supports 25-400G KP/KR/LL FEC
  • Supports only the System PLL clocking mode
  • Supports only the Duplex operation mode
  • Supports the gearbox feature

You can enable FEC Direct mode in the IP parameter editor by turning on the Enable RS-FEC option, as RS-FEC (Reed Solomon Forward Error Correction) Options describes. FEC direct modes (KP,KR,LL) with FEC specifications are topology-dependent to achieve different BER. FEC data to and from the PCS is 33b. On the PMA interface side, FEC data from and to the PMA interface is 40b wide.

FEC Direct Mode with System PLL Clocking and Gearbox Enabled

Enabling Gearbox in RS-FEC Mode

For designs that include FEC, gearbox enables automatically. The gearbox options are 32:40, 64:80, and 128:160. Firecode FEC supports the 32:33 gearbox ratio. For designs that include a PCS (Physical Coding Sublayer) only, the only option is the 32:33 gearbox ratio.

Table 25.  FEC Direct IP Configuration Mode Support
Mod Type PMA Type FEC Mode Clock Mode Width PMA Width

PMA

Interface

FIFO

(Tx/Rx)

F-tile

Interface

FIFO

(Tx/Rx)

Core

Interface

FIFO

(Tx/Rx)

NRZ FGT

RS(528, 514), RS(272,258),

RS(544, 514)

Sys PLL DW 32

Elastic/

Elastic

Phase Compensation/

Phase Compensation

Phase Compensation/

Phase Compensation

FHT

RS(528, 514), RS(272,258),

RS(544, 514)

Sys PLL DW 32,64

Elastic/

Elastic

Phase Compensation/

Phase Compensation

Phase Compensation/

Phase Compensation

PAM4 FGT

RS(528, 514), RS(272,258),

RS(544, 514)

Sys PLL DW 32,64

Elastic/

Elastic

Phase Compensation/

Phase Compensation

Phase Compensation/

Phase Compensation

FHT

RS(528, 514), RS(272,258),

RS(544, 514)

Sys PLL DW 32, 64, 128

Elastic/

Elastic

Phase Compensation/

Phase Compensation

Phase Compensation/

Phase Compensation