
SAMSUNG
Version: TM 2.4
KS9245 ATAPI Automated CD-ROM Controller
Preliminary Technical Manual
_____________________________________________________________
Do Not Copy or Release
2-2
ATA Features Register (Read)
AFEAT
BIT 6
BIT 5
BIT 4
Reserved (Tag Type)
Acronym:
BIT 7
Rsvd
BIT 3
BIT 2
BIT 1
Overlap
BIT 0
DMA
Reserved
The ATAPI Features Register contains the specific features (such as DMA/PIO mode or Overlap
Operation) which the host requests the drive to perform.
Bit 7-2: Reserved
These bits are reserved for future enhancements.
Bit 1: Overlap
When this bit is set during the issuance of an ATAPI Packet Command, the KS9245 may release
the ATA bus prior to the completion of that Packet Command. In this case, the KS9245 will use
the
Release
bit in it’ s
ATAPI Interrupt Reason Register
(Reg02h, bit2) to inform the host that it has
released the ATA bus before completing the command in progress.
Bit 0: DMA
When DMA bit is set, data transfers for the command will use the DMA channel. When the DMA
bit is cleared, data transfers for the command will be PIO mode. Firmware uses this bit to
configure PIO or DMA mode for host data transfers. The
ATA Transfer Mode
bits in the
Interface
Configuration Control Register
(Reg0Bh, bits6,5) are used to select various transfer modes.
Register 01h :
ATAPI Error Register (Write)
ATA Error Register (Write)
AERR
BIT 5
BIT 4
Sense Key
Acronym:
BIT 7
BIT 6
BIT 3
MCR
BIT 2
ABRT
BIT 1
EOM
BIT 0
ILI
The
ATAPI Error Register
contains the errors at the command process or completion stage. The
firmware must set the appropriate error bits and Sense Key code when an error occurs in the
command processing stage.
Bit 7-4: Sense Key
These bits contain the Sense Key information.
Bit 3: MCR (Media Change Requested)
When this bit is set, it indicates that a media change has occurred.
Bit 2: ABRT (Abort)
When this bit is set, it indicates that the command has been aborted.
Bit 1: EOM (End of Media)
When this bit is set, it indicates that the end of media has been reached.