C141-E039-01EN
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3.4.4
READ BUFFER (3C)
Bit
Byte
7
6
5
4
3
2
1
0
0
X‘3C’
1
LUN
0
0
Mode
2
X‘00’ (Buffer ID)
3
Buffer Address (MSB)
4
Buffer Address
5
Buffer Address (LSB)
6
Transfer Byte Length (MSB)
7
Transfer Byte Length
8
Transfer Byte Length (LSB)
9
0
0
0
0
0
0
Flag
Link
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 IDD has a 512 K (524,288) byte size data buffer. In this command, each data byte
position in the data buffer must be specified in 2-byte units using buffer addresses within the
range X ‘000000’ to Cache segment volume – 2, in even numbered addresses.
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.
“Mode” Bit
2
1
0
Transfer Mode
0
0
0
Data, without Address Specification
0
0
1
Data, with Address Specification
0
1
0
Data Only, with Address Specification
0
1
1
Buffer Descriptor