Hitachi HDS723020BLA642 - General Operation Descriptions; Reset Response

Hitachi hard disk drive specifications
56
9 General Operation Descriptions
9.1 Reset Response
There are three types of reset in ATA as follows:
Power On Reset (POR)
The device executes a series of electrical circuitry diagnostics, spins
up the HDA, tests speed and other mechanical parametric, and sets
default values.
COMRESET
COMRESET is issued in Serial ATA bus.
The device resets the interface circuitry as well as Soft Reset.
Soft Reset (Software Reset)
SRST bit in the Device Control Register is set, and then is reset.
The device resets the interface circuitry according to the Set Features
requirement.
The actions of each reset are shown in Table 28.
POR
COMRESET
Soft Reset
Aborting Host interface
-
o
o
Aborting Device operation
-
(*1)
(*1)
Initialization of hardware
o
x
x
Internal diagnostic
o
x
x
Spinning spindle
o
x
x
Initialization of registers (*2)
o
o
o
Reverting programmed parameters to default
o
(*3)
(*3)
- Number of CHS
(set by Initialize Device Parameter)
- Multiple mode
- Write cache
- Read look-ahead
- ECC bytes
Disable Standby timer
o
x
x
Power mode
(*5)
(*4)
(*4)
o ---- execute
x ---- not execute
Table 28 Reset Response
Table Notes
(*1) Execute after the data in write cache has been written.
(*2) Default value on POR is shown in 0 Default Register Values on page57.
(*3) The Set Features command with Feature register = CCh enables the device to revert these
parameters to the power on defaults.
(*4) In the case of Sleep mode, the device goes to Standby mode. In other case, the device does
not change current mode.
(*5) Idle when Power-Up in Standby feature set is disabled. Standby when Power-Up in Standby
feature set is enabled.