Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
204
18.15
PRE-FETCH (90)
Table 172 PRE-FETCH (90)
Byte
Bit
7
6
5
4
3
2
1
0
0
Command Code = 90h
1
Reserved = 0
Reserved = 0
Immed = 0
Reserved = 0
2-9
(MSB)
Logical Block Address
(LSB)
10-13
Transfer Length
14
Restricted
For MMC-4
Reserved = 0 GROUP NUMBER = 0
15
VU = 0
Reserved = 0
FLAG
LINK
The PRE-FETCH command requests the drive to transfer data to the cache. No data is transferred to the Initiator.
- Transfer length field specifies the number of contiguous blocks of data that are to be transferred into the
cache. A transfer length of zero indicates that blocks are to be transferred into the cache until the segment is
filled or until the last block on the media.
- Immed (Immediate) must be zero. An immediate bit of zero indicates that the status shall not be returned until
the operation has completed.
If the Immed bit is set to one, the drive returns a Check Condition status. The sense key shall be set to Illegal
Request and the additional sense code shall be set to Invalid Field in CDB6) - (08)