Quantum ProDrive 40S - WRITE and VERIFY Command

Section 5
SCSI Programming Guidelines
TRANSFER LENGTH (Bytes 7-8) - Specifies the number of contiguous logical blocks of data
that will
be transferred. A transfer length of zero indicates that no logical blocks will be transferred.
This condition will not
be considered an error and no data will be written. Any other value indicates
the number
of logical blocks that will be transferred.
5.11.19 SEEK EXTENDED COMMAND: OPCODE = 2B(hex)
The SEEK EXTENDED command (Table 5-35) requests that the logical unit seek to the specified logical
block address.
TABLE 5-35 SEEK EXTENDED Command
Bit 7
I
6
I
5
I
4
I
3
I
2
I
1
I
0
Byte
0
OPCODE=2BH
I
LUN-O
I
RESERVED-O
~F.T.AnR=O
2-5
(MSB)
LOGICAL BLOCK ADDRESS
(LSB)
6-8 RESERVED =0
9 VU=O
I
RESERVED=O
I
F
I
L
5.11.20 WRITE AND VERIFY COMMAND: OPCODE = 2E(hex)
The WRITE AND VERIFY command (Table 5-36) instructs the ProDrive to write the data transferred
from the initiator to the medium and verify that the data is written correctly.
TABLE .5-36 WRITE AND VERIFY Command
Bit 7
I
6
I
5
1
4
I
3
1
2
I
1
I
0
Byte
0
OPCODE=2EH
1
LUN-O
I
RESERVED =0
I BYTCHK kEI.ADR=(]
2-5
(MSB)
LOGICAL BLOCK ADDRESS
(LSB)
6 RESERVED =0
7-8
(MSB)
TRANSFER
LENGTH
(LSB)
9
VU=()
I
RESERVED =0
I
F
I
L
BYTCHK - BYTE CHECK (Byte 1, Bit 1) - Must be set to zero. The ProDrive only
supports medium verification (ECC) (BYTCHK set to zero); it does not support a byte-to.-byte
comparison
of the data on the medium and the data sent from the initiator (BYTCHK set to one).
If this bit is set to one, the command will be tenninated with a CHECK CONDITION status with
ILLEGAL
REQUEST sense key.
LOGICAL BLOCK ADDRESS (Bytes 2-5) - Specifies the logical block at which the write
operation is
to begin.
·5-62 SCSI Programming Guidelines