Message System; Table 3-4 Messages - Sun Microsystems storagetek sl500 Reference Manual

Message System

Message System
The message system allows SCSI devices to communicate for physical path
management. There are two ways to transfer messages during the Information
Transfer phase:
Message In
Message Out
The ATN signal prompts the target to start the Message Out phase. The Message
Out phase is the next phase entered by the target; however, it can start at any time
after detecting an Attention condition.
If the target receives any message other than Identify, Abort, or Bus Device Reset as
the first message after selection, the target aborts the operation and enters the Bus
Free phase.

TABLE 3-4 Messages

Hex Code
00
01
02
03
04
05
06
07
08
09
0C
80–FF
Note: In = Target to initiator, Out = Initiator to target
In general, SCSI supports two types of messages:
Messages containing a single byte
■
Messages containing multiple bytes
■
The following sections describe the valid messages along with their hexadecimal
code values.
24 SL500: Interface Reference Manual • July 2008
Messages from the target to the initiator
Messages from the initiator to the target
TABLE 3-4 lists the valid messages for the library:
Description
Command Complete
Extended
Save Data Pointers
Restore Pointers
Disconnect
Initiator Detected Error
Abort
Message Reject
No Operation
Message Parity Error
Bus Device Reset
Identify
Direction
In
Out
In
In
In
Out
Out
In/Out
Out
Out
Out
In/Out
Revision: F • 96122