
5.SCSI Interface
5.3.6.INITIATOR DETECTED ERROR (05h)
This message is sent from an initiator to inform a target that an error (e.g.: parity error) has occurred that does not prevent the target from
This message will not be sent by the drive, when the drive is acting as an initiator. When received as a target the unit will enter the status phase reporting CHECK CONDITION with the sense key set to COMMAND ABORTED.
5.3.7.ABORT (06h)
This message is sent from the initiator to the target to clear the present operation. All pending data and status from the affected logical unit is cleared, and the target goes to the BUS FREE phase. This message can be sent to a logical unit that is not currently performing an operation for the initiator.
A transaction which has not yet been acknowledged with a good Status byte will cause the transaction to be aborted. If a transaction has already been acknowledged, the abort will force a Write of any pending data. The device will proceed directly to BUS FREE state.
5.3.8.MESSAGE REJECT (07h)
This message is sent from either the initiator or target to indicate that the last message it received was inappropriate or has not been implemented.
In order to indicate its intentions of sending this message, the initiator asserts the ATN signal prior to its release of ACK for the REQ ACK handshake of the message that is to be rejected. Message Reject is issued in response to any messages which the unit considers to be illegal or not supported. The illegal message will cause the current command to be aborted and the unit will enter the status phase reporting CHECK CONDITION with the sense key set to COMMAND ABORTED.
When received as a target, if the unit was previously in Message In phase (i.e.: sending messages to the host) then MESSAGE REJECT will cause the unit to go straight to the Status phase with a CHECK CONDITION status and a sense key of COMMAND ABORTED. If the unit was not previously in Message In phase then MESSAGE REJECT will be handled as an illegal message.
If the initiator sends MESSAGE REJECT message in response to the units DISCONNECT message, the unit will disable disconnects for the rest of the nexus and continue.
5.3.9.NO OPERATION (08h)
This message is sent by an initiator in response to a target’s request for a message when the initiator does not currently have any other valid message to send. This message is accepted when the drive is acting as a target, and may be sent when it is an initiator. When a
5.3.10.MESSAGE PARITY ERROR (09h)
This message is sent from the initiator to the target to indicate that one or more bytes in the last message it received had a parity error.
To indicate its intentions of sending this message, the initiator will send the ATN signal prior to its release of ACK for the REQ/ACK handshake of the message that has the parity error. This provides an interlock so that the target can determine which message has the parity error.
This message will not be sent by the drive, when the drive is acting as an initiator. When received as a target, the unit will enter the Status phase reporting CHECK CONDITION with the sense key set to COMMAND ABORTED.
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