Smart Subcommand | Hitachi A7K2000, HCS721050CLA382, HCS721032CLA382

11.42.1 SMART Subcommand

In order to select a subcommand the host must write the subcommand code to the device‟s Features Register before issuing the SMART Function Set command. The subcommands and their respective codes are listed below.

Code	Subcommand
D0h	SMART Read Attribute Values
D1h	SMART Read Attribute Thresholds
D2h	SMART Enable/disable Attribute Autosave
D3h	SMART Save Attribute Values
D4h	SMART Execute Off-line Immediate
D5h	SMART Read Log Sector
D6h	SMART Write Log Sector
D8h	SMART Enable Operations
D9h	SMART Disable Operations
Dah	SMART Return Status
DBh	SMART Enable/Disable Automatic Off-Line

11.42.1.1SMART Read Attribute Values (Subcommand D0h)

This subcommand returns the device‟s Attribute Values to the host. Upon receipt of the SMART Read Attribute Values subcommand from the host, the device saves any updated Attribute Values to the Attribute Data sectors, and then transfers the 512 bytes of Attribute Value information to the host.

11.42.1.2SMART Read Attribute Thresholds (Subcommand D1h)

This subcommand returns the device‟s Attribute Thresholds to the host. Upon receipt of the SMART Read Attribute Thresholds subcommand from the host, the device reads the Attribute Thresholds from the Attribute Threshold sectors, and then transfers the 512 bytes of Attribute Thresholds information to the host.

11.42.1.3SMART Enable/Disable Attribute Autosave (Subcommand D2h)

This subcommand enables and disables the attribute autosave feature of the device. The SMART Enable/Disable Attribute Autosave subcommand either allows the device to automatically save its updated Attribute Values to the Attribute Data Sector periodically; or this subcommand causes the autosave feature to be disabled. The state of the Attribute Autosave feature (either enabled or disabled) will be preserved by the device across power cycle.

A value of 00h written by the host into the device‟s Sector Count Register before issuing the SMART Enable/Disable Attribute Autosave subcommand will cause this feature to be disabled. Disabling this feature does not preclude the device from saving Attribute Values to the Attribute Data sectors during some other normal operation such as during a power-up or power-down.

A value of F1h written by the host into the device‟s Sector Count Register before issuing the SMART Enable/Disable Attribute Autosave subcommand will cause this feature to be enabled. Any other non-zero value written by the host into this register before issuing the SMART Enable/Disable Attribute Autosave subcommand will not change the current Autosave status but the device will respond with the error code specified in 0.

The SMART Disable Operations subcommand disables the autosave feature along with the device‟s SMART operations.

Upon the receipt of the subcommand from the host, the device asserts BSY, enables or disables the Autosave feature, clears BSY and asserts INTRQ.

Hitachi hard disk drive specifications

205 HCS721016CLA382, HCS721050CLA382, HCS721025CLA382, HDP725050GLA360, HUA722050CLA330/1 specifications

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