F-Tile Triple-Speed Ethernet Intel® FPGA IP User Guide

ID 741328
Date 2/09/2023

A newer version of this document is available. Customers should click here to go to the newest version.

Document Table of Contents

A.3. Pause Frame Format

A pause frame is generated by the receiving device to indicate congestion to the emitting device. If flow control is supported, the emitting device should stop sending data upon receiving pause frames.

The length/type field has a fixed value of 0x8808, followed by a 2-octet opcode field of 0x0001. A 2-octet pause quanta is defined in the second and third bytes of the frame payload (P1 and P2). The pause quanta, P1, is the most significant byte. A pause frame has no payload length field, and is always padded with 42 bytes of 0x00.

Figure 78. Pause Frame Format