SAA7385 Datasheet, PDF (39/64 Pages) NXP Semiconductors – Error correction and host interface IC for CD-ROM SEQUOIA

Philips Semiconductors
Error correction and host interface IC for
CD-ROM (SEQUOIA)
Preliminary specification
SAA7385
11.6 53CF94 related registers
In the 53CF94 SCSI controller, some registers are read only and others are write only. These share the same address
and the multiplexing between the two depends on the read or write select.
This part contains only a brief description of the register definitions. For a more detailed definition, see the data sheet for
the SCSI device.
Table 57 Transfer count registers: 0xF0A4, F0A5 and F0BE- 53CF94 addresses: 0x00, 01, 0E; note 1
DATA BYTE
MNEMONIC R/W
7
6
5
4
3
2
1
0
TCLOW
R/W DATA7 DATA6 DATA5 DATA4 DATA3 DATA2 DATA1 DATA0
TCMID
R/W DATA7 DATA6 DATA5 DATA4 DATA3 DATA2 DATA1 DATA0
TCHIGH
R/W DATA7 DATA6 DATA5 DATA4 DATA3 DATA2 DATA1 DATA0
Note
1. These registers form the 24-bit transfer count value for DMA operations; they specify the number of bytes that are
transferred.
Table 58 FIFO buffer register: 0xF0A6 - 53CF94 address 0x02; note 1
DATA BYTE
MNEMONIC R/W
7
6
5
4
3
2
1
0
FIFO
R/W DATA7 DATA6 DATA5 DATA4 DATA3 DATA2 DATA1 DATA0
Note
1. The FIFO is a 16 × 9-bit buffer between the SCSI interface and the memory. The SCSI command packet will be
present in this FIFO ready to be read by the microcontroller at the end of the SCSI command phase.
Table 59 Command register: 0xF0A7 - 53CF94 address 0x03; note 1
DATA BYTE
MNEMONIC R/W
7
6
5
4
3
2
1
0
CMD
R/W ENDMA
COMMAND6 to COMMAND0
Note
1. The command register is a two-deep read/write register used to pass commands to the SCSI controller; up to two
commands can be stacked at the same time. When ENDMA is set, the command is a DMA instruction.
Table 60 Status register and destination ID: 0xF0AC - 53CF94 address 0x04; note 1
DATA BYTE
MNEMONIC R/W
7
6
5
4
3
2
1
0
STAT
R
INT
GE
PE
TC
VGC
MSG
C/D
I/O
STAT
W
−
−
−
−
−
ID2
ID1
ID0
Note
1. This register contains the flags indicating the occurrence of certain events.
1996 Jun 19
39