IBM IC35L018UCDY10, Specifications

Page: 207 / 249

10.4 SCSI Bus Related Error Handling Protocol
This protocol is used to handle errors that threaten the integrity of a connection between the Target and
an initiator.
10.4.1 Unexpected BUS FREE Phase Error Condition
There are several error conditions that will cause the drive to immediately change to the BUS FREE phase
regardless of the state of the ATN signal. The drive will not attempt to reconnect to the initiator to complete
the operation that was in progress when the error condition was detected. The initiator should interpret this
as a catastrophic error condition.
If the LUN was identified by the drive prior to the error condition, the drive will abort the active command
for this initiator/LUN and generate sense data for this initiator/LUN to describe the cause of the cata-
strophic error. The initiator may retrieve this sense data by issuing a REQUEST SENSE command to this
LUN. Note however, that the REQUEST SENSE command may fail if the catastrophic error condition
persists.
If the LUN was not identified by the drive prior to the error condition, the drive will not affect the sense data
or the operation of any currently executing command for this initiator or any other initiator.
10.4.2 MESSAGE OUT Phase Parity Error
The drive will optionally retry the message phase and, if it still fails, abort the current command with
CHECK CONDITION status and sense data of ABORTED COMMAND / SCSI PARITY ERROR. If the
parity error occurs before the ITL nexus is established (on the initial IDENTIFY message), the drive is to
go to the bus free state.
10.4.3 MESSAGE IN Phase Parity Error (MESSAGE PARITY ERROR)
The drive may retry the message phase and, if it still fails, abort the current command and go to bus free,
setting sense data of ABORTED COMMAND / SCSI PARITY ERROR.
10.4.4 COMMAND Phase Parity Error
The drive may retry the command phase after sending a restore pointers message. If it still fails, it will
abort the current command with CHECK CONDITION status and sense data of ABORTED COMMAND /
SCSI PARITY ERROR.
10.4.5 DATA OUT Phase Parity Error
If the drive detects a parity error during DATA OUT phase, the drive will abort the current command with
CHECK CONDITION status and sense data of ABORTED COMMAND / SCSI PARITY ERROR.
Ultrastar 146Z10 hard disk drive specifications
191