Log Sense 4Dh - Sony AIT-SDX460 Product Specifications Manual

7. ATAPI Packet Command Specification
7.6.

LOG SENSE 4Dh

Bit 7
Byte
0
1
2 PC
3 (MSB)
4
5
6
7 (MSB)
8
9
10
11
LOG SENSE provides a means for the Host to retrieve statistical information maintained by the device about its
own hardware or the installed media. It is a complementary command to the LOG SELECT command.
SP: The device does not have non-volatile RAM into which it may save parameters. Therefore, the Save Page bit
is not supported by this device and shall always be set to ZERO. If the SP bit is set, the command will be
terminated with CHECK CONDITION status with the sense key set to ILLEGAL REQUEST, and an additional
sense code of INVALID FIELD IN CDB.
PPC: The Parameter Pointer Control bit shall always be set to ZERO. This indicates that the parameter data
requested from the device will start with the parameter code specified in the Parameter Pointer field and return the
number of bytes specified in the Allocation Length field in ascending order of parameter codes from the specified
log page. A PPC bit of ZERO and a Parameter Pointer field of ZERO cause all available parameter data for that
page code to be returned to the initiator. If the PPC bit is set or the Parameter Pointer is larger than the highest
numbered parameter on the page, then the target shall terminate the command with CHECK CONDITION status.
The sense key shall be set to ILLEGAL REQUEST and the additional sense code shall be set to INVALID FIELD
IN CDB. If the drive does not support a parameter code within this page then it shall not return any data
associated with this parameter.
PC: The Page Control field defines the type of parameter values to be selected. The page control field is defined
below:
The Current Threshold Values and the Default Threshold Values are non-changeable and will both return the
same values-i.e. the maximum values that each parameter can attain. Note that for some parameters the term
threshold value has no meaning. See the description of individual pages/ parameters below for more details.
The Current Cumulative Values are the values computed since the last reset of the device (either by power-cycling,
ATA RESET). Note that for some parameters these values cannot be reset by any method. See description of
individual pages/parameters below for more details.
The Default Cumulative Values are the values to which each parameter gets initialized on a reset condition as
described above. See description of individual pages/parameters below for more details.
7-12
6 5
Reserved
Table 7-10: LOG PAGE Page Control Field Values
Value
00b
01b
10b
11b
4 3
Operation Code (4Dh)
Page Code
Parameter Pointer
Allocation Length
Reserved
Reserved
Reserved
Description
Current Threshold Values
Current Cumulative Values
Default Threshold Values
Default Cumulative Values
SONY AIT-1Turbo drive SDX-460V series Ver.1.0
LOG SENSE
2 1 0
Reserved Reserved
(PPC) (SP)
(LSB)
(LSB)