3.3.2
Set Features command (EF
H
)
The host uses the Set Features command (command code EF
H
) to
establish parameters that affect the execution of certain drive features.
To use the command:
1. Write the Feature value to the Features register.
2. Write the Set Features command to the command register.
Note. If the value in the Features register is not supported or is invalid,
the drive posts an Aborted Command error.
At power-on, or after a hard reset, the feature selections are restored to
the factory-default values. If 66
H
has been set, a software reset does not
change the feature selections (this can be canceled by setting CC
H
). If
66
H
has not been set, a soft reset returns the settings to the factory
defaults.
The following table shows alterable features supported by the ST3295A
and ST3660A drives. Where a factory default value exists, that value is
listed.
Byte
Feature description
02
H
Enable write cache (factory default).
03
H
Set value for Set Transfer mode based on value in Sector
Count register.
44
H
Use maximum length of ECC (16 bytes) on read long/write
long commands (factory default).
55
H
Disable read look-ahead feature.
66
H
Use current settings as default (until hard reset or power off).
77
H
Disable ECC.
82
H
Disable write cache.
88
H
Enable ECC (factory default).
AA
H
Enable read look-ahead feature (factory default).
BB
H
4 bytes of ECC apply on read long/write long commands.
CC
H
Enable reverting to power-on defaults (factory default).
26
Medalist XE Family Product Manual, Rev. B
