System and method for ethernet per priority pause packet flow control buffering

Abstract

A method is provided for managing a transmit buffer using per priority pause flow control. An Ethernet transceiver generates packet descriptors identifying packets to be transmitted that are stored in memory. A priority is assigned to each descriptor and associated packet. Each descriptor is loaded into a queue having a queue priority associated with the descriptor priority. In response to accessing a first descriptor, output from a selected first priority queue, a first packet associated with the first descriptor is fetched into a transmit buffer from the memory. If subsequent to fetching the first packet, a per priority flow control message is received pausing first priority packets, the first packet is flushed from the transmit buffer. Then, a second descriptor is accessed from a selected second priority queue, and a second packet associated with the second descriptor is fetched and transmitted from the transmit buffer.