Technical information

HGST Ultrastar C15K600 Hard Disk Drive Specification
227
18.26
READ LONG (9E)
Table 203 READ LONG (9E)
Byte
Bit
7
6
5
4
3
2
1
0
0
Command Code = 9Eh
1
Reserved = 0
Service Action (11h)
2-9
(MSB)
Logical Block Address
(LSB)
10-11
Reserved = 0
12-13
(MSB)
Byte Transfer Length
(LSB)
14
Reserved = 0
PBLOCK
CORRCT
15
VU = 0
Reserved = 0
FLAG
LINK
The READ LONG command requests the drive to transfer one block of data to the Initiator. The transfer data
includes data and MEDC field data.
- Correct transferred bit of zero causes correction to be attempted, data will be returned without reporting media
errors regardless of the drives ability to successfully make corrections. When this bit is set the drive will return
media errors if correction is not successful.
- Logical Block Address field specifies the logical block at which the read operation shall occur.
- Byte Transfer Length field must specify exactly the number of bytes of data that are available for transfer. If a
non-zero byte transfer length does not match the available data length, the Target terminates the command with
Check Condition status, the sense key is set to Illegal Request, and an additional sense code set to Invalid
Field in CDB. The valid and ILI bits are set to one and the information field is set to the difference of the
requested length minus the actual length in bytes. Negative values are indicated by two's complement notation.
The transfer length is calculated as follows:
transfer length = logical block size + 18
The data read by this command is neither read from nor retained in the cache. Data returned by this command can
not be corrupted and transferred on a subsequent WRITE LONG command to create recoverable media errors.