Low Latency 40G Ethernet Intel® FPGA IP User Guide: Agilex™ 5 FPGAs and SoCs

ID 813652
Date 4/01/2024
Public
Document Table of Contents

5. Clocking and Reset Requirements

The transmit clock (clk_txmac) is derived from TX IOPLL. The reference frequency is the output from the GTS tx_clkout [0]. The PLL converts the frequency from 161.13 MHz to 312.5 MHz. This clock is guaranteed stable when tx_ready is high.

The receive clock (clk_rxmac) is derived from RX IOPLL. The reference frequency is the output from the UX rx_clkout [0]. The PLL converts the frequency from 161.13 MHz to 312.5 MHz. This clock is guaranteed stable when rx_is_lockedtodata is high.

The transceiver calibration clock must be between 100 MHz and 125 MHz as set by the PMA blocks.

The Avalon® memory-mapped clock (clk_status) is nominally 100 MHz but can be as high as 125 MHz.

Figure 11. Clocks