E-Tile Hard IP User Guide: E-Tile Hard IP for Ethernet and E-Tile CPRI PHY Intel® FPGA IPs

ID 683468
Date 7/23/2024
Public
Document Table of Contents

2.11.11. Deterministic Latency Interface

The E-Tile Hard IP for Ethernet Intel FPGA IP Deterministic Latency Interface is available when you turn on Include deterministic latency measurement interface for 10G/25G channels in 100GE or 1 to 4 10GE/25GE with optional RS-FEC and 1588 PTP variation.

Note: This feature is for internal use only, do not enable this setting.

When setting is turned on, you can view the deterministic latency interface directly from the Stratix® 10 E-Tile Transceiver Native PHY.

Use the deterministic latency interface if you want to measure the latency of the datapath when running a stack that does not include MAC.
Note: Exposing deterministic latency interface does not change the Ethernet operation. Ethernet protocol does not use this interface. Enabling this feature exposes the interface from Stratix® 10 E-Tile Transceiver Native PHY to the user.
Note: Refer to the E-Tile CPRI PHY IP in Deterministic Latency Calculation for an example of the interface usage.
Table 45.  Signals of the Deterministic Latency InterfaceAll of the Deterministic Latency Interface signals are asynchronous.

Signal Name

Width

Description

o_tx_dl_async_pulse[ch-1:0] 1

Asynchronous output pulse signal for the transmitter latency measurement 28 of the deterministic latency application. There is a start pulse and a stop pulse.

o_sl_rx_dl_async_pulse[ch-1:0] 1

Asynchronous output pulse signal for the receiver latency measurement28 of the deterministic latency application. There is a start pulse and a stop pulse.

i_sl_latency_sclk[ch-1:0] 1

Clock signal for latency measurement28 of the deterministic latency application.

i_sl_tx_dl_measure_sel[ch-1:0] 1

Mux select signal for the transmitter latency measurement.28 1 is for the datapath latency. 0 is for the wire delay.

i_sl_rx_dl_measure_sel[ch-1:0] 1

Mux select signal for the receiver latency measurement.28 1 is for the datapath latency. 0 is for the wire delay.

28 For more information, review the Latency Measurement section.