Flow Control - 7.2 English

AXI 1G/2.5G Ethernet Subsystem Product Guide (PG138)

Document ID
PG138
Release Date
2023-11-15
Version
7.2 English

The flow control function is defined by IEEE Std 802.3-2008 Clause 31. The subsystem can be configured to send pause frames and to act upon the pause frames received. These two behaviors can be configured independently (asymmetrically). To enable or disable transmit and receive flow control, see the FCC register in the Tri-Mode Ethernet MAC LogiCORE IP Product Guide (PG051).

Flow control can be used to prevent data loss when an Ethernet interface is unable to process frames fast enough to keep up with the rate of frames provided by another Ethernet interface. When this occurs, the overloaded interface can transmit a pause control frame to request that the link partner (the device connected on the other end of the Ethernet) stops transmitting for a defined period of time.