3.4.4
READ BUFFER (3C)
Bit
Byte
0
1
2
3
4
5
6
7
8
9
This command is used in combination with the WRITE BUFFER command to diagnose the normalcy of
the IDD's data buffer memory and the SCSI bus.
The functions of this command and the contents of the data transferred to the INIT are specified by the
"Mode" field in the CDB and one of the transfer modes shown below can be selected.
3
"Mode" Bit
0
0
0
0
1
1
(1)
Mode = 0, 0, 0, 0: Header + data, without address specification
When this mode is specified, the data stored in the IDD's data buffer are transferred to the INIT after the
4-byte header. Zero must be specified in the "Buffer offset" field in the CDB.
C141-C010
7
6
5
LUN
X'00' (Buffer ID)
Buffer Offset (MSB)
Buffer Offset
Buffer Offset (LSB)
Transfer Byte Length (MSB)
Transfer Byte Length
Transfer Byte Length (LSB)
0
0
0
2
1
0
0
0
0
Header + Data, without Address Specification
0
0
1
Header + Data, with Address Specification
0
1
0
Data Only, with Address Specification
0
1
1
Buffer Descriptor
0
1
0
Echo buffer
0
1
1
Echo buffer descriptor
3.4 Maintenance, Diagnostic Commands
4
3
2
X'3C'
0
Mode
0
0
0
Transfer Mode
1
0
0
Link
3-115