Fujitsu MHW2040AT - Mobile 40 GB Hard Drive, Product Manual

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5.3 Host Commands
(28) SET FEATURES (X’EF’)
The host system issues the SET FEATURES command to set parameters in the
Features register for the purpose of changing the device features to be executed.
Upon receipt of this command, the device sets the BSY bit of the Status register
and saves the parameters in the Features register. Then, the device clears the BSY
bit, and generates an interrupt.
If the value in the Features register is not supported or it is invalid, the device
posts an ABORTED COMMAND error.
Table 5.23 lists the available values and operational modes that may be set in the
Features register.
Table 5.23 Features register values and settable modes
Features
Register
Drive operation mode
X’02’ Enables the write cache function.
X’03’ Set the data transfer mode. *1
X’05’ Enables the advanced power management function. *2
X’42’ Enables the Acoustic management function. *3
X’55’ Disables read cache function.
X’66’ Disables the reverting to power-on default settings after software reset. (*1)
X’82’ Disables the write cache function.
X’85’ Set the advanced power management mode to Mode-0.
X’AA’ Enables the read cache function.
X’BB’ Specifies the transfer of 4-byte ECC for READ LONG and WRITE LONG
commands. (*1)
X’C2’ Disables the Acoustic management function.
X’CC’ Enables the reverting to power-on default settings after software reset. (*1)
*1 Although there is a response to the command, nothing is done.
At power-on or after hardware reset, the default mode is set as follows.
Write cache function : Enabled
Transfer mode : PIO Mode-4, Multiword DMA Mode-2
Advanced power
management function : Enabled (Mode-1)
Acoustic
management function
: State keeping
Read cache function : Enabled
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