If the requestor is busy, does the bus just wait until the requestor can receive the response?
@huehue I don't think so. One of the main requirements from this system was the ability for caches to respond to bus requests even though they might also be servicing processor requests. If the requestor couldn't respond to the 'Data req', it would prevent any other processor from receiving their responses. Therefore, I would presume that the requestor immediately ACKs (to signal intent to receive) or NACKs (to signal that it's busy and can't receive it now) the 'Data req'.