Release Interrupt; Set Transfer Mode; 12.39.2 Write Cache; Advanced Power Management - Hitachi T7K250 - Deskstar - Hard Drive Specifications

Note: After the power on reset or hard reset the device is set to the following features as default.
Write cache
ECC bytes
Read look-ahead
Reverting to power on defaults

Release interrupt

12.39.1 Set Transfer mode

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.
PIO Default Transfer Mode
PIO Default Transfer Mode, Disable IORDY
PIO Flow Control Transfer Mode x
Multiword DMA mode x
Ultra DMA mode x

12.39.2 Write Cache

If the number of auto reassigned sectors reaches the reassignment capacity of the device, the write cache function
will automatically be 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 (word 85 or 129) in Table 73: "Identify device information (Part 1 of 7)" on page 128.

12.39.3 Advanced Power Management

When the Feature Register is 05h (=Enable Advanced Power Management) the Sector Count Register specifies the
Advanced Power Management level.
FFH Aborted
The lowest Power Saving Mode is Normal Idle mode (the same as Disable
C0-FEh
Advanced Power Management)
80-BFh The lowest power consumption mode is Low Power Idle
01-7Fh The lowest power consumption mode is Low RPM standby mode
00H Aborted
The idle time to Low power idle mode and Low RPM standby mode vary according to the value in Sector Count
register as follows:
When Low power idle mode is the deepest Power Saving mode,
= (x − 80h) 5+ 120
y
1
=N/A
(the device does not go to Low RPM standby mode)
y
2
When Low RPM standby mode is the deepest Power Saving mode and the value in Sector Count register is
between 40h and 7Fh,
00000 000
00000 001
00001 nnn (nnn=000,001,010,011,100)
00100 nnn (nnn=000,001,010)
01000 nnn (nnn=000,001,010,011,100,101)
(120 ☯y
☯435)
[sec]
1
Deskstar T7K250 Hard Disk Drive Specification
Enable
4 bytes
Enable
Disable
Disable
189