IBM IC25N020ATDA04 - Travelstar 20 GB Hard Drive - Page 178

Output Parameters To The Device
Feature Destination code for this command.
02H Enable write cache
(See note 2)
03H Set transfer mode based on value in sector count register
05H Enable Advanced Power Management
09H Enable Address Offset mode
44H 40 bytes of ECC apply on Read Long/Write Long commands
55H Disable read look-ahead feature
66H Disable reverting to power on defaults
82H Disable write cache
85H Disable Advanced Power Management (See note 3)
89H Disable Address Offset mode
AAH Enable read look-ahead feature
BBH 4 bytes of ECC apply on Read Long/Write Long commands
CCH Enable reverting to power on defaults
Note 1. When the Feature register is 03h ( = Set Transfer mode) the Sector Count Register specifies the
transfer mechanism. The upper 5 bits define the type of transfer and the low order 3 bits encode the mode
value.
(nnn=000,001,010,011,100, 101)nnn01000Ultra DMA mode x
(nnn=000,001,010)nnn00100Multiword DMA mode x
(nnn=000,001,010,011,100)nnn00001PIO Flow Control Transfer Mode x
00100000
PIO Default Transfer Mode,
Disable IORDY
00000000PIO Default Transfer Mode
When the Feature register is 05h ( = Enable Advanced Power Management) the Sector Count Register
specifies the Advanced Power Management level.
Aborted00h, FFh ...
The deepest Power Saving mode is Standby01h–7Fh ...
The deepest Power Saving mode is Low power Idle80h–BFh ...
The deepest Power Saving mode is Active IdleC0h–FEh ...
Note 2. If the number of auto reassigned sectors reaches the device's reassignment capacity, the write
cache function will be automatically disabled. Although the device still accepts the Set Features command
(with Feature register = 02h) without error, the write cache function will remain disabled. For the current
write cache function status, refer to the Identify Device Information (129 word) by the Identify Device
command. Hard reset or power off must not be done in 5 seconds after write command completion when
write cache is enabled.
Note 3. When the Feature register is 85h (= Disable Advanced Power Management) the deepest Power
Saving mode becomes Active Idle.
Travelstar 48GH, 30GN & 15GN hard disk drive specifications
164