Hitachi HDS723020BLA642 General Operation Descriptions, Reset Response, Register Initialization

7K200 SATA OEM Specification

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” on Page 50

Aborting Host interface

Aborting Device operation

Initialization of hardware

Internal diagnostic

Starting spindle motor

Initialization of registers (*2)

Reverting programmed parameters to default

-Number of CHS (set by Initialize Device Parameter)

-Multiple mode

-Write cache

-Read look-ahead

-ECC bytes

-Volatile max address

Power mode

Reset Standby timer value

POR

-

-

O

O

(*5)

O

O

(*5)

o

COMRESET

o

(*1)

x

x

x

o

(*6)

(*4)

o

Soft Reset

o

(*1)

x

x

x

o

(*3)

(*4)

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 51.

(*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

12.1.1Register Initialization

After power on, COMRESET, or software reset, the register values are initialized as shown in the following table.

50/173