130 Product Manual - Disc Drive SCSI-2/SCSI-3 Interface (Vol. 2; Ver. 2), Rev. E
_____________________________________________________________________________________
For defects to be specified in the Physical Sector format, the Defect List format field (Byte 1, bits 2, 1, 0) must
be 101 (binary). See Tables 5.2.1-3 and 5.2.1-4.
Each Defect Descriptor for the Physical Sector format specifies a sector size defect location comprised of the
cylinder number of the defect, the head number of the defect and the defect sector number.
The Defect Descriptors shall be in ascending order. The drive may return CHECK CONDITION if the defect
descriptors are not in ascending order. For determining ascending order, the Cylinder Number of the defect
is considered the most significant part of the address and the Defect Sector Number is considered the least
significant part of the address.
A Defect Sector Number of FFFFFFFFh (i.e., reassign the entire track) is illegal for the disc drive.
5.2.1.3
Reassign Blocks Command (07h)
Table 5.2.1-7. Reassign Blocks Command
Bit
7
6
5
4
3
2
1
0
Byte(s)
0
0
0
0
0
0
1
1
1
1
Logical Unit No.[1]
0
0
0
0
0
0
0
0
2
0
0
0
0
0
0
0
0
3
0
0
0
0
0
0
0
0
4
0
0
0
0
0
0
0
0
5
0
0
0
0
0
0
Flag Link [2]
Notes.
[1] The LUN must be zero.
[2] See “Control Byte” paragraph 4.2.6.
The Reassign Blocks command (Table 5.2.1-7) requests the target to reassign the defective logical blocks to
an area on the logical unit reserved for this purpose.
After sending the Reassign Blocks command, the initiator transfers a defect list that contains the logical block
addresses to be reassigned. The disc drive reassigns the physical medium used for each logical block
address in the list. The data contained in the logical blocks specified in the defect list is not preserved, but the
data in all other logical blocks on the medium is preserved. It is recommended that the initiator recover the
data from the logical blocks to be reassigned before issuing this command. After completion of this com-
mand, the initiator can write the recovered data to the same Logical Block Addresses.
The effect of specifying a logical block to be reassigned that has previously been reassigned is to reassign
the block again. Thus, over the life of the medium, a logical block can be assigned to multiple physical
addresses (until no more spare locations remain on the medium).
This command should be used by an initiator to immediately reallocate any block (sector) which requires the
disc drive to recover data by data correction via ECC if the automatic reallocation feature of the disc drive is
not enabled, see Mode Select command (Section 5.2.1.7).
