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Cautions in Specifying the D List
The P List, containing defect position information, is always recorded on the IDD when it
is shipped from the factory. Also, information on defect positions for which alternate
block processing has been implemented during operation are recorded as the G List. The
function which specifies defect position information as the D List when the FORMAT
UNIT command is executed, is prepared mainly to specify initial defect position
information of the disk media which does not have the P List recorded on it. In the IDD,
by specifying use of the P List and G List, advance notice of the defect positions can be
specified during initialization, so ordinarily, it is not necessary to use the D List. When the
D List is used for the IDD, caution should be exercised in the follow points.
1.
The following formula is applied for the maximum number (p = n + m) of defective
sectors (logical data blocks) which make alternate block processing (sector slip or
alternate sectors) necessary.
n + 2m ≤ 9,945
where,
n is the number of defective sectors to which "sector slip" processing is applied, and
m is the number of defective sectors to which "alternate sector" processing is applied.
See Chapter 3 "Data Format" of the "Product Manual" concerning alternate block
processing methods. If defect processing which exceeds this limit is specified in the
FORMAT UNIT command, that command is terminated with a CHECK
CONDITION status (HARDWARE ERROR [=4] / No defect spare location available
[-32-00]).
2.
A defect descriptor specified as the D List are received normally if the specified defect
position information is within a range which does not exceed the disk drive's physical
boundaries (User Space), and is recorded as the G List, but formatting processing is
executed only for the User Space in the range specified in the "Block descriptor" and
"Format parameters" (Page 3), and the "Drive parameters" (Page 4) of the MODE
SELECT parameter.
3.
If a defect descriptor in the "Byte distance from the Index format" is specified in the
D List, depending on the byte position of the specified defective byte, 2 sectors may
be processed as defective sectors with one defect descriptor, or 1 sector may be
processed as a defective sector with 2 or more defect descriptors.
specified defective byte position has no influence on data block read/write operations,
that defect position information is disregarded and is not the object of defective sector
processing, and thus is not recorded in the G List. Therefore, the defect position
information specified in this command may not necessarily coincide with the defect
position information read with the READ DEFECT DATA command after this
command is terminated.
C141-E039-01EN
Also, if the
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