Hitachi Ultrastar 15K450 (FC-AL) Hard Disk Drive Specification
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19.7 LOG SENSE (4D)Table 117:Log Sense (4D)
The LOG SENSE command allows the Initiator to retrieve the statistical data regarding the drive.
•PPC (Parameter Pointer Control) bit must be set to zero. This specifies that the drive start transferring data starting from
the field specified in the parameter pointer field for the number of bytes specified by the allocation length. If the PPC
bit is set to 1, Check Condition status is returned with a sense key of Illegal Request and additional sense code of
Invalid Field in CDB.
•SP (Save Parameters) bit set to 0 specifies that the drive does not save any log parameters. If it is set to 1, all page param-
eters that are savable (those pages denoted by a DS = 0 in the parameter header control byte) are saved.
•PC (Page Control) field defines the type of parameters to be selected. This field must be set to 01b to specify the current
cumulative values. Any other value in this field will cause the command to end with a Check Condition status with a
sense key of Illegal Request and an additional sense code of Invalid Field in CDB.
•Page Code field identifies which page is being requested. This field must be set to the values indicated in Page 0. If the
Page Code value is invalid a Check Condition status is returned with a sense key of Illegal Request and additional
sense code of Invalid Field in CDB.
•Parameter Pointer Field specifies the beginning field for the transfer. This field must be set to 0000h. If the Parameter
Pointer Field is not zero a Check Condition status is returned with a sense key of Illegal Request and additional sense
code of Invalid Field in CDB.
•Allocation Length field specifies the maximum number of bytes the Initiator has allocated for returned Log Sense Data.
No bytes are transferred if the length is zero. This condition is not considered an error. TheTarget terminates the Data
In phase when all available Log Sense data has been transferred or when the number of bytes equals the allocation
length, whichever is less.
Byte Bit
76543210
0 Command Code = 4Dh
1 Reserved = 0 Reserved = 0 PPC=0 SP
2 PC Page Code
3
4Reserved = 0
5
6
(MSB) Parameter Pointer = 0
(LSB)
7
8
(MSB) Allocation Length
(LSB)
9 Reserved = 0 FLAG LINK