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Command Specifications
3 -
80
C141-E167
• Immed (Immediate)
“1” : If “1” is specified in the Immed (immediate) bit, at the point when the CDB’s
legality is confirmed, or at the point when transfer of the defect list is completed, a
“GOOD” status is reported.
“0” : If “0” is specified in the Immed (immediate) bit, the specified operation is executed
and the status byte is reported at the point when that operation is completed, then the
command is terminated.
• Defect list length
This field specifies the total number of bytes in the “Defect list” transferred from the INIT
following the header. The byte length of the “Defect descriptor” which configures the
defect list differs depending on its format and the value specified by this field must be a
multiple of 4 when the defect descriptor is in the block address format, and must be a
multiple of 8 when the defect descriptor is in the byte distance from the index format or the
physical sector address format. When zero is specified in this field, it indicates that the
defect list is not transferred.
Note:
The disk media defect processing method implemented during FORMAT UNIT
command execution is specified by the CDB and by header of the format parameters
transferred from the INIT. By specifying zero in the “Defect list length” field in the
Format parameter header, the INIT can specify the control flags related to formatting
processing without transferring the defect list (D List).
b. Defect list (D List)
The defect list (D List) contains defect position information about the disk media specified by
the INIT and is configured from one or more “Defect descriptors.” “Defect descriptors must be
described in the format specified in the “Defect List Format” field of the CDB.
The configurations which it is possible to specify for the “Defect descriptors” in the defect list
(D List), and their description formats, are shown below. Furthermore, it is possible only to
specify User Space address information on the disk media in the Defect list (D List).
• Byte distance from the index format defect descriptor
Figure 3.14 shows this description format of the defect descriptor. Defect descriptor in this
format specifies the cylinder number, head (track) number and byte distance to the top byte
of those data (8 bytes), of the data which includes defective bits, on the disk media. One
defect is treated as a defect with a length of 8 bytes (64 bits length). Therefore, for defects
with a length which exceeds 8 bytes, 2 or more defect descriptors must be specified. When
multiple defect descriptors are specified, the cylinder number must be specified in the top
position, the byte distance from the index in the bottom position, and the defect positions
listed in ascending order.