TXDAT

Function Description

The TXDAT module unconditionally receives requests from MainPipe destined for the WDAT channel, buffers them using a queue, and finally sends them to the CHI TXDAT bus channel. The TXDAT module needs to perform flow control on the MainPipe entrance to ensure that requests on MainPipe can enter TXDAT without being blocked.

Function Description

Feature 1: Back Pressure on MainPipe

To ensure that requests on MainPipe can enter TXDAT non-blockingly at s3/s4/s5, when [the number of requests on MainPipe that might need to enter TXDAT + the number of valid items in the queue ≥ the total number of queue items], the TXDAT module needs to apply back pressure on the MainPipe entrance, i.e., at the s0/s1 stage. 1. Back pressure is applied at the s1 stage because snoops received by RXSNP might be processed directly on MainPipe and then enter the TXDAT channel, therefore, back pressure is needed for sinkB requests at s1. 2. Back pressure is applied at the s0 stage because a portion of MSHR tasks need to enter the TXDAT channel, and MSHR tasks enter the pipeline at s0, therefore, back pressure is needed for mshrTask at s0.

TXDAT