In reply to jyotsna:
Hi jyotsna,
i can not give you ans with out existing AHB code, but if we consider top level change then you have to maintain out-of-order transaction mainly and also use hook that can change addr data as per AXI standers, and you can also use defines to select mode like AXI or AHB , if possible also add hook in driver so you get more flexible control on driver.