5K250 (SATA) OEM Specification
Page 48 of 171
12
General Operation Descriptions
12.1
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, then is reset.
The device resets the interface circuitry according to the Set Features requirement.
The actions of each reset are shown in “Table 29 Reset Response Table”
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
Starting spindle motor
(*5)
x
x
Initialization of registers (*2)
O
o
o
Reverting programmed parameters to default
O
(*6)
(*3)
- Number of CHS (set by Initialize Device Parameter)
- Multiple mode
- Write cache
- Read look-ahead
- ECC bytes
- Volatile max address
Power mode
(*5)
(*4)
(*4)
Reset Standby timer value
o
o
x
O ---- execute
X ---- not execute
Note.
(*1) Execute after the data in write cache has been written.
(*2) Default value on POR is shown in “
Table 30 Default Register Values
” on Page 49.
(*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) According to the initial power mode selection.
(*6) See
12.15
Software Setting Preservation Feature Set
.
Table 29 Reset Response Table
12.1.1
Register Initialization
After power on, COMRESET, or software reset, the register values are initialized as shown in the following table.
