5. Serial ATA Interface
SONY AIT-1 Turbo drive SDX-470V series Ver.1.0
5-3
Device/Head register
The DEV bit becomes effective when this register is written by the host or the signature is set by the device. All
other bits in this register become a command parameter when the Command register is written.
7 6 5 4 3 2 1 0
obsolete
#
obsolete
DEV
# # # #
- obsolete - These bits are obsolete.
NOTE - Some hosts set these bits to one. Devices shall ignore these bits.
- # - The content of these bits is command dependent.
- DEV - Device select. Cleared to zero selects Device 0. Set to one selects Device 1.
Error register
This register contains status for the current command. Following a power on, a hardware or software reset, or
command completion of an EXECUTE DEVICE DIAGNOSTIC or DEVICE RESET command, this register contains
a diagnostic code.
At command completion of any command except EXECUTE DEVICE DIAGNOSTIC, the contents of this register
are valid when the ERR bit is equal to one in the Status register.
7 6 5 4 3 2 1 0
# # # # #
ABRT
# #
- Bit 2 - ABRT (command aborted) is set to one to indicate the requested command has been command
aborted because the command code or a command parameter is invalid or some other error has occurred.
- # -The content of this bit is command dependent.
Features register
The content of this register is command dependent and becomes a command parameter when the Command
register is written.
Sector Count register
The content of this register is command dependent and becomes a command parameter when the Command
register is written.
Sector Number register
The content of this register is command dependent and becomes a command parameter when the Command
register is written.
Status register
This register contains the device status. The contents of this register are updated to reflect the current state of the
device and the progress of any command being executed by the device.
7 6 5 4 3 2 1 0
BSY DRDY # DSC DRQ obsolete
obsolete ERR
BSY is set to one to indicate that the device is busy. After the host has written the Command register the device
shall have either the BSY bit set to one, or the DRQ bit set to one, until command completion or the device has
performed a bus release for an overlapped command.
DRDY is set to one to indicate that the device is ready to accept a new command.
DSC is used with ATAPI packet commands to provide efficient use of the IDE bus by allowing overlapped
commands to be sent to the other IDE Device on the same cable while the SDX-470V is executing a command.
This field is not supported.