
W88111AF/W88112F
Preliminary/Confidential
ATAPI CD-ROM Decoder & Controller
This specification is subject to change without notice.
Publication Release Date: Aug, 1996
Preliminary/ Confidential Revision A0.1
- 45 -
BSY(37h.7)
←
1
PDIAGEN (20h.6)
←
0 and disables pin PDIAGb to high-impedance state
CKSTP (19h.7)
←
0
ATAPI Error Register
←
01h
ATAPI Feature Register
←
00h
ATAPI Interrupt Reason Register
←
01h
ATAPI SAM Tag Byte
←
01h
ATAPI Byte Counter Register Low/High
←
00h
ATAPI Drive Select Register
←
00h
Clear ATAPI Status Register except bit BSY and SERVICE
Activates host interrupt to the microprocessor if HIIEN (2Eh.7) is enabled
Bit 4: SHDC - Shadow Command Flag
This bit becomes high when the host writes a command to a non-existent slave drive. Meanwhile,
UINTb becomes low-active if SHIEN (2Eh.2) is enabled. ATAC is de-activated by the following:
Chip reset or host reset
Reading register ATCMD (37h)
Writing 1 to CLRBSY (20h.4)
Bit 3: ARST - ATAPI Soft Reset Flag
This bit becomes high when ATAPI Soft Reset command (opcode 08h) is written to either master
or slave drive. ARST is de-activated by writing any value to register ARSTACK (30h).
Bit 2: RST - Reset Flag
This bit is high when the chip is currently being reset by chip reset, host reset, or firmware reset.
Bit 1: FRST - Firmware Reset Flag
This bit is high if the current or most recent reset was firmware reset. The first read of register
MISS1 (2Fh) following the end of the firmware reset clears FRST to 0.
Bit 0: HRST - Chip reset or host reset Flag
This bit is high if the current or most recent reset was activated by chip reset or host reset. The
BSY flag is set whenever chip reset or host reset is activated. The first read of register MISS1
(2Fh) following the end of the chip reset or host reset clears HRST to 0.
ARSTACK - ATAPI Soft Reset Acknowledge (write 30h)
Writing any value to register ARSTACK triggers the following events: