Low Latency 40G for ASIC Proto Ethernet Intel® FPGA IP User Guide

ID 683221
Date 11/10/2022
Public
Document Table of Contents

6.5. Transceivers

The transceivers require a separately instantiated advanced transmit (ATX) PLL to generate the high speed serial clock. For Low Latency 40G for ASIC Proto Ethernet IP core, you can use the same ATX PLL for all four transceivers. In many cases, the same ATX PLL can serve as input to additional transceivers that have similar input clocking requirements. In comparison to the fractional PLL (fPLL) and clock multiplier unit PLL, the ATX PLL has the best jitter performance and supports the highest frequency operation.
Table 17.   Transceiver Signals

Signal

Direction

Description

tx_serial[3:0] Output TX transceiver data. Each tx_serial bit becomes two physical pins that form a differential pair.
rx_serial[3:0] Input RX transceiver data. Each rx_serial bit becomes two physical pins that form a differential pair.
clk_ref Input The PLL reference clock. Input to the clock data recovery (CDR) circuitry in the RX PMA. The frequency of this clock is .