Triple-Speed Ethernet Intel® FPGA IP User Guide

ID 683402
Date 11/25/2022

A newer version of this document is available.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

Document Table of Contents Multiport MAC FIFO Status Signals

The MAC FIFO status interface is an Avalon streaming sink port which streams in information on the fill level of the external FIFO buffer to the MAC function.
Table 72.  MAC FIFO Status Signals
Signal Name Avalon Streaming Signal Type I/O Description
rx_afull_valid_n valid I Assert this signal to indicate that the fill level of the external FIFO buffer, rx_afull_data_n[1:0], is valid.
rx_afull_data_n[1:0] data I Carries the fill level of the external FIFO buffer:

rx_afull_data_n[1]—Set to 1 if the external receive FIFO buffer reaches the initial warning level indicating that it is almost full. Upon detecting this, the MAC function generates pause frames.

rx_afull_data_n[0]—Set to 1 if the external receive FIFO buffer reaches the critical level before it overflows. The FIFO buffer can be considered overflow if this bit is set to 1 in the middle of a packet transfer.

rx_afull_channel[(CHANNEL_WIDTH-1):0] channel I The port number the status applies to.
rx_afull_clk clk I The clock that drives the MAC FIFO status interface.
Table 73.  References
Interface Signal Section
Clock and reset signals Clock and Reset Signals
MAC control interface MAC Control Interface Signals
MAC transmit interface MAC Transmit Interface Signals
MAC receive interface MAC Receive Interface Signals
Status signals MAC Status Signals
Pause and magic packet signals Pause and Magic Packet Signals
PHY management signals PHY Management Signals
ECC status signals ECC Status Signals