Table of Contents
Advertisement
BIT
BYTE
07
06
05
04
03
02
01
00
------1------1------ ------1------1------1------1-------
00
Group Code
Opcode
01
Logical Unit Number
Command Specific Bits
IREL ADR
03
04
05
06
07
08
09
(MBS)
-
-
-
- -
-
-
-
-
- - -
-
-
- - - -
Loglcal Block Address
-
-
-
-
-
-
-
-
- - -
-
- -
-
-
-
-
Logical Block Address
-
- -
-
-
- - -
- - - - -
-
- - - -
Logical Block Address
-
-
-
-
-
- - - -
- -
-
-
-
Logical Block Address
(LSB)
Reserved
Number of Blocks
Number of Blocks
Reserved (0)
1
Flag
1
Link
Figure 4-4.
Group 1 Commands (l0-Byte Extended Block Address)
4.4.2
GROUP CODE
The group code can be 0 to 7 indicating the SCSI command group.
The ACB-5500 uses only 0 and 1 to indicate Group 0 (6 byte) and
Group 1 (10 byte) Commands.
4.4.3
OPERATION CODE
The operation code indicates to the controller the command to be
executed.
The operation code allows for 32 commands (00 HEX to
IF HEX).
4.4.4
LOGICAL UNIT NUMBER
Logical Unit Numbers identify up to 8 devices attached to a
controller.
The ACB-5500 accepts Logical Unit Numbers from 0 to
3, addressing 4 SMD disk devices per controller.
The Logical
Unit Number is only examined and used by the ACB-5500 if the
IDENTIFY message was not provided.
500504-00
4-19
Advertisement
Table of Contents
