Errors Detected By The Drive - Tandberg Data SLR7-140 PROGRAMMER Manual

Tandberg Data
7.6.1.

Errors Detected by the Drive

When a bus parity error has been detected in a SELECTION
phase, the selection will be ignored by the Drive.
When detecting a bus parity error in the COMMAND, DATA
OUT or MESSAGE OUT phases the drive may retransfer the
command, data burst or the message. If the parity error
persists, the drive
until the Bus
exhausted. The
configurable (see the Bus Parity Error Retry field in
the Miscellaneous Parameters mode page).
When a bus parity error has been detected in the COMMAND
phase, the Drive will go to the to MESSAGE IN phase and
transfer a RESTORE POINTERS message. The Drive will then
go back to the COMMAND phase and the Command Descriptor
Block will be transferred once more from the Initiator.
When transferring Command Descriptor Blocks, the Drive
will stop the transfer immediately when a parity error
has been detected. If the parity error persists and the
Bus Parity Error Retry count has been exhausted (or if
the Bus Parity Error Retry has been configured to 0),
the drive will
CONDITION status. The Error Code will be SCSI P
E .
RROR
When a bus parity error has been detected in a DATA OUT
phase, the Drive will go to the MESSAGE IN phase and
transfer a RESTORE POINTERS message. The Drive will then
go back to the DATA OUT phase and the data transferred
since the last reconnect (or COMMAND phase) will be
transferred once
transferring Data
complete burst before taking any action on bus parity
errors. When a bus parity error has been detected, the
Drive will ensure
written to the tape. If the parity error persists and
the Bus Parity Error Retry count has been exhausted (or
if the Bus Parity Error Retry has been configured to 0),
the drive will
CONDITION status. The Error Code will be SCSI P
E . If the erroneous burst is a part of a large block
RROR
(split in several transfers), then the complete block
will not be written on tape.
If a parity error is detected during a MESSAGE OUT
phase, the Target will consume all the remaining bytes
in the message and ask for re-transfer of the whole
message. If the parity error persists and the Bus Parity
Error Retry count has been exhausted (or if the Bus
Parity Error Retry has been configured to 0), the drive
will go to the BUS FREE phase (creating an Unexpected
Bus Free condition).
If ATN is deasserted before the expected number of bytes
is transferred, the Target will send a REJECT MESSAGE
back to the Initiator.
If ATN is still asserted after the expected number of
bytes is transferred, the Target goes to the BUS FREE
state.
7-10 Tandberg SLR Product Line SCSI Functional Specifications
will repeat
Parity Error Retry
Bus Parity Error
terminate the
more from the
Out, the Drive
that the erroneous
terminate the
General Exception Handling
the retry operation
count has
Retry count
command with CHECK
Initiator.
will transfer
burst is
command with CHECK
been
is
ARITY
When
a
not
ARITY