Re: [ethmac] AMBA AHP Interface

[Billditt@aol.com]

I believe ARM has the AMBA specification available via their
website. 
   Its a good specification,  I have a couple of recommendations:
    1. Dont sweat split transactions
    2. Dont sweat wrapping bursts
    3. Watch the size vs bytes selects.
          Many busses do byte/word/Dword alignment using bytesels.
         AMBA doesnt. AMBA uses size and address to align transfers.
    For instance, for 32 bit AMBA bus, transferring 3 bytes of a 4 byte 
     Dword. AMBA breaks these up into 2 transfers, a word (with aligned
    address) and a byte (with byte aligned address). 
    
    This becomes kind of a pain when you are going from a bytesel based system
    to AMBA. And if you are doing bursts (most busses do) , its an even bigger
    pain. But AMBA is the most used SOC bus today, so I guess we live with it.
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