5-150 Maxtor Atlas 10K V
5.46 WRITE AND VERIFY Command (2Eh)
The WRITE AND VERIFY command writes host-supplied data to the unit and
verifies it was written correctly. The data format and field descriptions are shown in
Table 5-210 and Table 5-211 respectively.
Table 5-210 WRITE AND VERIFY Command Descriptor Block-Data Format
Table 5-211 WRITE AND VERIFY Command-Field Descriptions
Bit
Byte
765 4 3210
0 Operation Code (2Eh)
1 Reserved DPO Reserved BytChk RelAdr
2 - 5 Logical Block Address
6 Reserved
7 - 8 Transfer Length
9 Control
Field Description
DPO
Disable Page Out. When the value of the field is 1, the drive tells the controller to by-
pass cache as much as possible. The buffers used for the WRITE data are given a low
priority. This bit may be useful if the host CPU is performing a background copy oper-
ation and does not want to wipe out the drive's cache.
When DPO is 0, the drive tells the controller to cache this WRITE data in a normal
manner.
NOTE: The drive normally assigns a low priority to write caching. Therefore, the DPO
bit in a WRITE command is essentially ignored.
BytChk
Byte Check. When 1, the drive performs a byte-by-byte comparison of the data written
on the media with the data transferred from the initiator.
When 0, the drive performs a medium verification with no data comparison of the sec-
tors written by the command.
RelAdr Relative Address. This feature is not supported and the field must be 0.
Logical Block
Address
The address of the first logical block where the WRITE operation will occur.
Transfer Length
The number of contiguous logical blocks of data to write and verify. The drive returns
CHECK CONDITION status with the correct sense data if the specified transfer would
cause the write operation to extend beyond the Logical Block Address space.
