F-Tile Low Latency 50G Ethernet Intel® FPGA IP User Guide

ID 758946
Date 4/03/2024
Public
Document Table of Contents

4. F-Tile Low Latency 50G Ethernet Intel® FPGA IP Parameters

The F-Tile Low Latency 50G Ethernet Intel® FPGA IP parameter editor provides the parameters you can set to configure the F-Tile Low Latency 50G Ethernet Intel® FPGA IP and design example.

The parameter editor includes an Example Design tab. For information about that tab, refer to the F-Tile Low Latency 50G Ethernet Intel® FPGA IP Design Example User Guide.

Table 6.  IP Parameters: Main Tab
Parameter Range Default Setting Description
General Options
Ready Latency 0, 3 0

Selects the readyLatency value on the TX client interface. readyLatency is an Avalon® streaming interface property that defines the number of clock cycles of delay from when the IP asserts the l1_tx_ready signal to the clock cycle in which the IP can accept data on the TX client interface. Refer to the Avalon® Interface Specifications.

Selecting a latency of 3 eases timing closure at the expense of increased latency for the datapath.

If you set the readyLatency to 3 and turn on standard flow control, data might be delayed in the IP while the IP is backpressured.

Core Variant MAC+PCS+PMA, MAC+PCS+PMA Selects the primary blocks to include in the IP variation.
  • MAC+PCS+PMA—The IP generates with the capability of MAC, PCS, and PMA protocol layers.
Flow Control Options
Enable flow control Enabled, Disabled Disabled When enabled, the IP implements flow control. When either link partner experiences congestion, the respective transmit control sends pause frames. Register settings in the Pause/PFC Flow Control Registers control flow control behavior, including whether the IP implements standard flow control or priority-based flow control.

If you turn on standard flow control and set the readyLatency to 3, data might be delayed in the IP while the IP is backpressured.

Number of queues 1-8 8 Specifies the number of queues used in managing flow control.
MAC Options
Enable link fault generation Enabled, Disabled Disabled When enabled, the IP implements link fault signaling as defined in the IEEE 802.3-2012 IEEE Standard for Ethernet. The MAC includes a Reconciliation Sublayer (RS) to manage local and remote faults. When enabled, the local RS TX logic can transmit remote fault sequences in case of a local fault and can transmit IDLE control words in case of a remote fault.
Enable preamble passthrough Enabled, Disabled Disabled When enabled, the IP is in RX and TX preamble pass-through mode. In RX preamble pass-through mode, the IP passes the preamble and Start Frame Delimiter (SFD) to the client instead of stripping them out of the Ethernet packet. In TX preamble pass-through mode, the client specifies the preamble and provides the SFD to be sent in the Ethernet frame.
Enable TX CRC passthrough Enabled, Disabled Disabled When enabled, TX MAC does not insert the CRC-32 checksum in the out-going frame. In pass-through mode, the client must provide frames with at least 64 bytes, including the Frame Check Sequence (FCS). When disabled, the TX MAC computes and inserts a 32-bit FCS in the TX MAC frame.
Enable MAC statistic counters Enabled, Disabled Enabled When enabled, the IP includes statistics counters that characterize TX and RX traffic.
Configuration, Debug and Extension Options
Reference clock frequency 156.25 156.25 Specifies the frequency of the transceiver CDR reference clock input in MHz.
Table 7.  IP Parameters: Analog Parameter Tab
Parameter Range Default Setting Description
FGT TX EQ
FGT TXEQ Post Tap 1, 1.0 step size 019 0 Options for FGT TX EQ Post Tap 1, in 1.0 step size increments.
FGT TXEQ Main Tap, 1.0 step size 055 35 Options for FGT TX EQ Main Tap, in 1.0 step size increments.
FGT TXEQ Pre Tap 1, 1.0 step size 015 5 Options for FGT TX EQ Pre Tap 1, in 1.0 step size increments.
FGT TXEQ Pre Tap 2, 1.0 step size 017 0 Options for FGT TX EQ Pre Tap 2, in 1.0 step size increments.
FGT RX
Select FGT Onchip Termination RX_ONCHIP_TERMINATION_R_1(85 Ohms)

RX_ONCHIP_TERMINATION_R_2(100 ohms)

RX_ONCHIP_TERMINATION_R_1(85_Ohms) Selects FGT RX termination resistor setting.
Enable FGT RX AC Couple DISABLE

ENABLE

ENABLE Enable RX external AC coupling setting.
Enable FGT VSR Mode VSR_MODE_LOW_LOSS

VSR_MODE_HIGH_LOSS

VSR_MODE_DISABLE

VSR_MODE_DISABLE Enable VSR mode setting.