format

+-----------+-----------+
|  Ver.     |  Type     |
+-----------------------+
|  CMD      |  FLAG     |
+-----------------------+
|           ID          |
+-----------------------+
|      Data Length      |
+-----------------------+
|    Address [31:24]    |
+-----------------------+
|    Address [23:16]    |
+-----------------------+
|    Address [15:8]     |
+-----------------------+
|    Address [7:0]      |
+-----------------------+
|         Data 0        |
+-----------------------+
|         Data 1        |
+-----------------------+
:                       :
:                       :
+-----------------------+
|         Data N        |
+-----------------------+

Ver. : fixed (0xF)
Type : fixed (0xF)
CMD  : 0x c for read
       0x 8 for write
       bit 3 : Access (Bus Access)
           2 : R/W 0: Write, 1: Read
           1 : Reserved.  Always 0
           0 : Reserved.  Always 0
FLAG : bit 3 : REQ/ACK 0:Request, 1:Ack
           2 : Reserved.  Always 0
           1 : Reserved.  Always 0
           0 : Error.     0: Normal, 1: Bus Error
ID: Ack packet will have same ID the requester has sent.
Data Length: More than 0 value.  Does not work if length = 0