Quantum ProDrive 40S - READ EXTENDED Command; WRITE EXTENDED Command

Section 5
SCSI Programming Guidelines
5.11.17 READ EXTENDED COMMAND: OPCODE = 28(hex)
The READ EXTENDED command (Table 5-33) requests that the target transfer data to the initiator.
TABLE 5-33 READ EXTENDED Command
Bit 7
I
6
I
5
I
4
I
3
J
2
I
1
I
0
Byte
0
OPCODE=28H
I
LUN=O
I
RESERVED =0
Lp'AOR=(J
2-5
. (MSB)
LOGICAL BLOCK ADDRESS
(LSB)
6
RESERVED =0
7-8
(MSB)
TRANSFER LENGTH
(LSB)
9
VU=O
I
RESERVED =0
I
F
I
L
LOGICAL BLOCK ADDRESS (Bytes 2-5)- Specifies the logical block at which the read
operation is to begin.
TRANSFER LENGTH (Bytes 7-8) - Specifies the number of con~iguous logical blocks of data
that are to be transferred. A transfer length
of zero indicates that no logical blocks are to be
transferred. This condition will not be considered an error. Any other value. indicates the number of
logical blocks that are to be transferred.
5.11.18 WRITE EXTENDED COMMAND: OPCODE = 2A(hex)
The WRITE EXTENDED command (Table 5-34) requests that the target write the data transferred by the
initiator to the medium.
TABLE 5-34 WRITE EXTENDED Command
Bit 7
t
6
I
5
I
4
I
3
I
2
I
1
I
0
Byte
0
OPCODE=2AH
1
LUN=O
I
RESERVED = 0
LRI.AOR::<J
2-5
(MSB)
LOOICAL BLOCK ADDRESS
{LSB}
6 RESERVED =0
7-8
(MSBl
TRANSFER LENGTH
(LSD)
9
VlJ=()
1
RESERVED =0
I
F
J
L
LOGICAL BLOCK ADDRESS (Bytes 2-5) - Specifies the logical block at which the write
operation is to begin.
SCSI Programming Guidelines 5-61