4.4 Maintenance, Diagnostic CommandsC141-C009 4-187(1) Mode = 0, 0, 0, 0: Header + data, without address specificationWhen this mode is specified, the data stored in the IDD’s data buffer aretransferred to the INIT after the 4-byte header. Zero must be specified in the“Buffer offset” field in the CDB.The “Transfer byte count” field in the CDB specifies the total number of bytes ofthe header and buffer data which can be received by the INIT. The IDD reads thedata from the data buffer from the top (Address X ‘000000’), then adds the 4-byteheader to it and transfers it to the INIT. Data transfer is completed at the pointwhen the number of bytes of the header and data from the IDD’s data buffer,specified in the “Transfer byte length” field, has been transferred, or at the pointwhen transfer of the header and all the data in the IDD’s data buffer, to the finalbyte position, has been completed. When zero is specified in the “Transfer bytelength” field, this command is terminated without executing a data transfer.The format of the data transferred to the INIT when this mode is specified isshown in Table 4.123Table 4.123 READ BUFFER command: buffer data (mode = 0000, 0001)BitByte 7 6 5 4 3 2 1 00 0 0 0 0 0 0 0 01 Effective Buffer Data Length (MSB)2 Effective Buffer Data Length3 Effective Buffer Data Length (LSB)4 Buffer Data (Byte 0)5 Buffer Data (Byte 1)n Buffer Data (Byte n–4)The “Effective buffer data length” field in the header indicates the size of the databuffer (byte length). This value indicates the size of the IDD’s data buffer thatcan be used by the WRITE BUFFER and READ BUFFER commands withoutrelation to the length specified in the “Transfer byte length” field in the CDB orthe length of the data actually stored in the data buffer by the WRITE BUFFERcommand. When this mode is specified, the “Effective buffer data length” showsthe size (cache segment volume) of the IDD’s entire data buffer area. Also, thelength of the buffer data transferred to the INIT by this command is the value forthe number of bytes in the [“Transfer byte length” field in the CDB – 4 bytes] orthe value indicated in the “Effective buffer data length” field in the header,whichever is smaller.~~ ~~~~HeaderData
