Target Error Conditions; Message Out Phase Parity Error; Command Or Data Out Phase Parity Error; Lllegal Messages - HP C2488A Technical Reference Manual

Extended SDTR Message
Target Error Conditions
The SDTR (SynChronous Data Transfer Request) message type will
only be accepted prior to the Command phase, and only prior to the
first Command phase in a linked command set. At any other time it
will be treated as an illegal message type. If the negotiation process is
started by the Initiator, the drive will respond with its SDTR message.
If the Initiate SDTR Message Option is enabled, the drive will initiate
an SDTR message a.t Power On and Reset.
Under some error conditions the Target may proceed to the Bus Free phase without
terminating the command (i.e. no Disconnect or Command Complete message sent to the
host). In this case, the Target will not attempt to re-connect with the Initiator. The Initiator
should consider this as a catastrophic error. Information regarding the cause of this abnormal
response can be recovered by the Initiator with the REQUEST SENSE command.
Message Out Phase Parity Error
If parity checking is enabled and a message out parity error is detected the disk drive will
abort the command in process and set the sense key to Aborted Command with the sense
code set to Parity Error. If a valid LUN has been received in an identify or in the CDB, and
status phase has not yet begun, then the command will be terminated with a Check Condition
status; otherwise, the Target will go the the Bus Free state.
Command or Data Out Phase Parity Error
If parity checking is enabled and a Command or Data Out phase parity error is detected then
disk drive will terminate the command in process with a Check Condition status. The sense
information will have the sense key set to Aborted Command with the sense code set to Parity
Error.
Illegal Messages
If an illegal or unexpected message out is received from the Initiator, the disk drive will abort
the command in process and set the sense key to Aborted Command with the sense code set to
Inappropriate/megal Message. If a valid LUN has been received in an identify or in the CDB,
and the status phase has not yet begun, then the command will be terminated with a Check
Condition status; otherwise the Target will go to the BUS FREE phase.
Reselection Timeout
If the Target attempts to reselect the Initiator and the Initiator does not respond within a
Selection Timeout Delay, the Target will attempt to reselect a second time. If the second
attempt fails, the Target will abort the command in process and make no further attempts to
reselect the host. The sense information will be set with a sense key of Hardware Error and a
sense code of Select/Reselect Failed.
4·8 SCSI Interface DRAFT
1/18/93 09:58