The design is using the MSGDMA component. I would like to export the "mm_read_waitrequest" signal from within "mm_read" interface. The tools only let you export the entire interface, or connect the interface, but not both. Furthermore, the Platform Designer On-line Training indicates that using a bridge component can be used to duplicate the interface. How is this accomplished?
A pipeline bridge has a master interface on one side and a slave on the other. So you would change something like this:
master -> slave
to something like this:
master -------> slave
----> slave (bridge) -> master (bridge; exported)
The bridge gets added to the address space of the master, so you have to make sure you set the bridge up with enough address bits. See this online training (it has other PD optimization techniques, but there is a slide on address coherency with pipeline bridges):