Seagate ST35040A, Руководство по эксплуатации продукта

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3.2.2 Set Features command (EF
H
)
The Set Features command (command code EF
H
) allows you to enable
and disable the multisegmented cache and Automatic Reallocation
features and to identify the transfer modes the drive uses. The multiseg-
mented buffer consists of Read Look-ahead and write-immediate and
write-merging features. The table below lists the features the drives
support. The features that are set to default by the factory are indicated
in the Feature column.
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 drives post an Aborted Command error.
At power-on or after a hard reset, the feature selections are restored to
the factory-default values.
The table below shows alterable features that the drives support. Values
that are preset at the factory are indicated as default in the feature
description.
Feature Value Feature
02
H
Enable write cache (default)
03
H
Set transfer mode
04
H
Enable Read Automatic Reallocation (default)
55
H
Disable read look-ahead cache
82
H
Disable write cache
84
H
Disable Read Automatic Reallocation
AA
H
Enable read look-ahead cache (default)
32 Medalist Pro 6450/5040 Product Manual, February 1997