7.7. Flow Control Signals
These signals are available only if Pause or PFC flow control support is synthesized. These indicates the MAC if a XON or XOFF Pause or PFC flow control frame should be sent.
FCQN = 1 for Pause
FCQN = 1 to 8 for PFC
The request for XON/XOFF flow control frame transmission can be done in either 1 or 2-bit request mode (see pause_insert_tx1).
1-bit mode request model:
2-bit mode request model:
Represents the lower bit. Only takes effect when the CSR of 2-bit Flow Control Request mode selects “Signal”.
Use in conjunction with pause_insert_tx0 to form a 2-bit request for XON/XOFF flow control frame transmission. This represents the upper bit of the 2-bit control.
|Asserted to indicate an RX pause signal match. The IP core asserts bit [n] of this signal when it receives a pause request with an address match, to signal the TX MAC to throttle its transmissions from priority queue [n] on the Ethernet link.