Datasheet

The Set Feature command establishes the following parameters which affect the execution of certain
features as shown in the table below
ABT will be set to 1 in the Error Register if the Feature register contains any undefined values.
Enable Power on Rest (POR) establishment of
defaults at Soft Reset
CCh
4 bytes of ECC apply on Read/Write Long commandsBBh
Enable Read Look AheadAAh
NOP n Accepted for backward compatibility9Ah
Accepted for backward compatibility. Use of this
feature is not recommended
97h
NOP n Accepted for backward compatibility96h
Disable Advanced Power Management85h
Disable Write Cache82h
Disable 8-bit data transfer81h
NOP n Accepted for backward compatibility69h
Disable Power on Reset (POR) establishment of
defaults at Soft Reset
66h
Disable Read Look Ahead55h
Product specific ECC bytes (34 bytes) apply o
n
Read/Write Long commands
44h
Set Advanced Power Management Mode05h
Used for Set Transfer Mode command03h
Enable Write Cache02h
Enable 8-bit data transfer01h
OperationFeature
Figure 98. Features Supported
Features 01h and 81h are used to enable and clear 8-bit data transfer modes in True IDE Mode. If the
01h feature command is issued all data transfers will occur on the low order D7-D0 data bus and the
IOIS16 signal will not be asserted for data register accesses.
Features 82h, AAh and BBh are the default features for the Hitachi Microdrive. Thus, the host does not
have to issue this command with these features unless it is necessary for compatibility reasons.
Features 66h and CCh can be used to enable and disable whether the Power On Reset (POR) Defaults
will be set when a soft reset occurs. The default setting is to revert to the POR defaults when a soft reset
occurs.
Feature 05h is used for advanced power management. The Sector Count Register specifies the
advanced power management level as below. The advanced power management level at power on reset
is 60h.
y 80h - FEh Up to Low Power Idle mode
y 01h - 7Fh Up to Standby mode
y 00h, FFh Reserved
Hard disk drive specification for DSCM-11000/-10512/-10340
117