Avalon-MM Master reading

If your master is fairly well self contained you might not need to write much testbench code. If it takes Avalon accesses to your core to start it up I would recommend using a bus functional model to start it up. Based on what you described I would suspect there could be a problem with the logic leading up to the first read. I would be careful since if your master is not following the spec due to a bug you could run into a really tricky corner later down the road that would be hard to debug. The fabric doesn't have much or any logic to 'fix up' the fabric after a master or slave violates the spec and those are some of the trickiest issues to debug from my own experience without simulating the system.