Function Set (B0H); Function Subcommands; Table 121: S.m.a.r.t. Function Set (B0H) - Hitachi HTS421212H9AT00 - Travelstar 120 GB Hard Drive Specifications

13.39 S.M.A.R.T. Function Set (B0h)

Table 121: S.M.A.R.T. Function Set (B0h)

Command Block Output Registers
Register
Data
Feature
Sector Count
LBA Low
LBA Mid
LBA High
Device
Command
7 6 5
CRC UNC 0
0 0 0
The S.M.A.R.T. Function Set command provides access to the Attribute Values, the Attribute Thresholds, and
other low level subcommands that can be used for logging and reporting purposes and to accommodate special user
needs. The S.M.A.R.T. Function Set command has several separate subcommands which are selectable via the
device's Features Register when the S.M.A.R.T. Function Set command is issued by the host. In order to select a
subcommand the host must write the subcommand code to the device's Features Register before issuing the
S.M.A.R.T. Function Set command. The subcommands and their respective codes are listed below
13.39.1 S.M.A.R.T. Function Subcommands
13.39.1.1 S.M.A.R.T. Read Attribute Values (subcommand D0h)
This subcommand returns the device's Attribute Values to the host. Upon receipt of the S.M.A.R.T. Read Attribute
Values subcommand from the host, the device asserts BSY, saves any updated Attribute Values to the Attribute
Data sectors, asserts DRQ, clears BSY, asserts INTRQ, and then waits for the host to transfer the 512 bytes of
Attribute Value information from the device via the Data Register.
13.39.1.2 S.M.A.R.T. Read Attribute Thresholds (subcommand D1h)
This subcommand returns the device's Attribute Thresholds to the host. Upon receipt of the S.M.A.R.T. Read
Attribute Thresholds subcommand from the host, the device asserts BSY, reads the Attribute Thresholds from the
Attribute Threshold sectors, asserts DRQ, clears BSY, asserts INTRQ, and then waits for the host to transfer the
512 bytes of Attribute Thresholds information from the device via the Data Register.
13.39.1.3 S.M.A.R.T. Enable/Disable Attribute Autosave (subcommand D2h)
This subcommand enables and disables the attribute auto save feature of the device. The S.M.A.R.T. Enable/Dis-
able Attribute Autosave subcommand allows the device to automatically save its updated Attribute Values to the
Attribute Data Sector at the timing of the first transition to Active idle mode and after 30 minutes after the last sav-
ing of Attribute Values. This subcommand causes the auto save feature to be disabled. The state of the Attribute
Autosave feature—either enabled or disabled—will be preserved by the device across the power cycle.
7 6 5 4 3 2 1 0
- - - - - - - -
V V V V V V V V
V V V V V V V V
- - - - - - - -
0 1 0 0 1 1 1 1
1 1 0 0 0 0 1 0
- - - D - - - -
1 0 1 1 0 0 0 0
Error Register
4 3 2 1
IDN 0 ABT T0N AMN
0 0 V 0
Travelstar 4K120 Hard Disk Drive Specification
Command Block Input Registers
Register
Data
Error
Sector Count
LBA Low
LBA Mid
LBA High
Device
Status
0 7 6 5
BSY RDY DF DSC DRQ COR IDX ERR
0 0 V 0
171
7 6 5 4 3 2 1 0
- - - - - - - -
see below
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
- - - - - - - -
see below
Status Register
4 3 2 1
V - 0 -
0
V