beautypg.com

Message in support – HP Q153090901 User Manual

Page 24

background image

Messages

24

Message In support

Name

Code Support

Command Complete

00h

This message is sent by the drive at the end of the status phase to

indicate that a command is complete. Once the message is sent, the

drive releases the bus and goes to Bus Free.

Disconnect

04h

This message is sent by the drive to indicate that it is about to

disconnect from the bus and go to Bus Free. During a Data phase, it is

always pre-ceded by a Save Data Pointers message. If a Message

Reject message is received in response to this message, then the

disconnect is prevented.

Extended Message

01h

See “Extended Message Support” below.

Identify

8

X

h

The Identify In message is sent to the initiator during reconnect to

indicate which Logical Unit is reconnecting.

Ignore Wide Residue

23h

This message is sent by the drive to the host to indicate that a byte on

a wide bus is not valid.
This is supported whenever a wide transfer is active. It should be sent

at the end of the data phase. The standard action of the drive is to

send this message between the data phase and the status phase with

no disconnect.

Message Reject

07h

This message is sent to the initiator when the message received by the

drive is unsupported or inappropriate.

Restore Pointers

03h

This message causes the initiator to reset its data transfer pointers to

the values they held when the last save data pointers message was

sent. It will be sent when a parity error is detected on the bus or when

an Initiator Detected Error message is received in order to retry the

data phase.

Save Data Pointers

02h

This message instructs the initiator to save its current data transfer

pointers for use with a subsequent Restore pointers message. This

message will always be sent before a Disconnect message during

data phases.