Why does the F-tile Ethernet FPGA Hard IP variant transmit XOFF frames at a rate roughly 20% lower than the expected XOFF transmission rate when enabling the Hold-off functionality?

Description

Due to a problem in the Quartus® Prime Pro Edition Software version 24.1, the F-Tile Ethernet FPGA Hard IP variant will transmit XOFF frames at a rate that is roughly 20% lower than the expected XOFF transmission rate based on the Hold-off Quanta contained in the “retransmit_xoff_holdoff_quanta” register.

Resolution

To work around this problem, you must account for the 20% deviation in the rate of transmitted XOFF frames when using the “retransmit_xoff_holdoff_quanta” register. 

This problem is not scheduled to be fixed.