2: increment register?
Byte 2 simply contains the hex for the address that you intend to modify. Bytes 3 and 4 are the length of the data to transfer in or out. 3 is most significant byte, 4 is least. After that comes the data. In a write you send the 4 bytes plus data, repeating as needed til the entire buffer is sent. In a read you send the 4 byte command and then read in data that is sent back.
The next step is to actually code the read/write functions into my driver now that I know how they work.
But first, I must play Mario Kart :)