Section 5 SCSI Programming Guidelines
5.11.10.3 Error Recovery Parameters. Page Code 1 H
Bit 7
6
5
4
3 2 1 o
Byte
o
RESERVED=O
PAGE
CODE = 1 H
1
PAGE
LENGTH
=
6H
2
AWRE
I
ARRE
I
1B
I
RC
I
EEC
I
PER
I
DTE
I
OCR
3
RETRY
COUNT
4 CORRECTION SPAN
5
HEAD
OFFSET COUNT = 0
6
DATA
STROBE OFFSET COUNT = 0
7
RECOVERY TIME LIMIT = 0
DCR - DISABLE CORRECTION (Byte 2, Bit
0)
- Set
to
one indicates that the data will
be
transferred without correction, whether
or
not it is possible to correct it. A OCR bit
of
zero indicates
that the data will
be
corrected
if
possible; uncorrectable data will
be
transferred with no attempt at
correction, although retries will still
be attempted.
If
RC (bit 4
of
byte 2) is set to one, this bit is
ignored. The default is zero.
DTE - DISABLE TRANSFER
ON
ERROR (Byte
2,
Bit
1)
- Set to one indicates that the
ProDrive will create the CHECK CONDITION status immediately upon detection
of
an error,
if
PER (bit 2
of
byte 2) is also set to one. Data transfer to the initiator will be terminated; the block in
error
mayor
may not
be
transferred to the initiator dependingon the setting
of
the TB bit. A DTE bit
set to zero enables data transfer for any data which can
be recovered within the limits
of
the Error
Recovery
Hags. Any errors that would
be
posted are not posted until the transfer length is exhausted.
If
PER is zero,
or
RC is one, this bit is ignored. The default is zero.
PER - POST ERROR (Byte 2, Bit
2)
-
Set
to zero indicates that the
ProDrive
will not
create the CHECK
CONDITION status for errors recovered within the limits established by the other
Error Recovery
Hags. Recovery procedures exceeding the limits established by the other Error
Recovery
Hags
will
be
posted. The transfer may terminate prior to exhausting the transfer length
depending on the error and state
of
the other Error Recovery Flags. A PER bit (bit 2
of
byte 2) set to
one will enable reporting
of
the CHECK CONDITION status for detected errors, with the appropriate
sense key.
If
multiple errors occur, the sense data will report the block address
of
the unrecoverable
error,if no unrecoverable error occurred, it will report the last block with recovered error. The default
is zero.
EEC - ENABLE EARLY CORRECTION (Byte 2, Bit 3) -
Set
to one indicates that the
ProDrive will use its ECC algorithm
if
two consecutive equal error syndromes (non-zero syndromes)
are detected.
It will not perform read retries before applying correction unless it determines the error
to
be
uncorrectable. Seek
or
positioning retries and the recovery procedure retries
of
the message
system are not affected by the value
of
this bit. An EEC bit set to zero indicates that the ProDrive
will use its normal recovery procedures when an error occurs. (See Appendix A for information on
ECC.)
If
the
RC
bit is one, this bit is ignored. The default is zero.
5-44
SCSI
Programming
Guidelines
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