I used to develop the bridge for the AMBA bus configuration, before end up using the AMBA IP from Synopsys. Whizkid is right, do read the AMBA 2.0 spec and put the emphasis on the bridge as well as the AHB and the APB protocol. Try grasp the basic idea of what the bridge is doing especially on READ/WRITE operations.
You can use this code for reference, as attached.
note: take a close look at the state machine part.