Maxtor ATLAS 10K III - Manual (Page 118)

SCSI Description
5-54 Maxtor Atlas 10K III
Table 5-71 Caching Page-(Page 8)
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&GHCWNV
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PS 1
Parameters Savable. This bit is only used with the MODE SENSE com-
mand. A returned value of 1 indicates that the target is capable of saving
the page in a non-volatile, vendor-specific location. Bit reserved with
MODE SELECT command.
WCE 1
Write Cache Enable. The default value of 1 enables write-back caching
when processing a WRITE command. When set to 0 the drive returns a
GOOD status and COMMAND COMPLETE only after successfully writing
all the data to the media.
When WCE = 1, write-back caching is enabled while processing a WRITE
command. The drive returns a GOOD status and COMMAND COMPLETE
only after fetching the data from the initiator and placing it in the drive’s
cache memory.
Note: For maximum data integrity, it is strongly recommended that when
WCE is set to 1, the Read-Write Error Recovery Page (01h) fields be set
as follows:
• AWRE to 1
• RC to 0
• DCR to 0
• Correction Span set to 170
• Head Offset to 0
• Servo Offset to 0
MF 0
Multiplication Factor (value must be 0). The drive interprets the minimum
and maximum pre-fetch fields values in terms of the number of logical
blocks for each of the respective types of prefetch.
RCD 0
Read Cache Disable. The default value of 0 enables the read cache capa-
bility and allows the drive to use cache-resident data or medium data to
satisfy a READ command.
When the value is 1, read caching is disabled and the data returned in re-
sponse to a READ command is fetched from the medium and not from the
drive’s cache memory.
Demand Read
Retention
Priority
0
This field advises the drive on the retention priority to assign data read into
the cache that has also been transferred from the drive to the initiator.
0QV
UWRRQTVGF D[ VJG FTKXG
Demand Write
Retention
Priority
0
This field advises the drive on the retention priority to assign data written
into the cache that has also been transferred from the cache memory to
the medium.
0QV UWRRQTVGF D[ VJG FTKXG
Disable
Pre-Fetch
FFFFh
This field specifies the selective disabling of anticipatory pre-fetch
Transfer
Length
on long transfer lengths. The value in this field is compared to the number
of sectors requested by the current READ command. If the number of sec-
tors is greater the than the value specified, anticipatory pre-fetch is not
performed for the command. When 0, anticipatory pre-fetch is disabled.
+IPQTGF D[ VJG FTKXG
Minimum
Pre-fetch
0
This field indicates the number of sectors that are to be pre-fetched. See
also MF.
Maximum
Pre-fetch
0421h
This field indicates the maximum amount of data to pre-fetch into the
cache as a result of one READ command.
0QV UWRRQTVGF D[ VJG FTKXG