msm82c55a-2gs Oki Semiconductor, msm82c55a-2gs Datasheet - Page 15

• Manufacturer Part Number: msm82c55a-2gs
• Description: Cmos Programmable Peripheral Interface
• Manufacturer: Oki Semiconductor

¡ Semiconductor
Port C Function Allocation in Mode 1
Port C
Examples of the relation between the control words and pins when used in mode 1 are
shown below:
(a) When group A is mode 1 output and group B is mode 1 input.
Combination of
Note: I/O is a bit not used as the control signal, but it is available as a port of mode 0.
Input/Output
PC
PC
PC
PC
PC
PC
PC
PC
Control Word
0
1
2
3
4
5
6
7
Group A: Input
Group B: Input
D
1
WR
7
RD
INTR
INTR
STB
STB
IBF
IBF
I/O
I/O
D
0
B
6
A
B
A
B
A
D
1
5
PA
PB
Group B: Output
PC
D
Group A: Input
0
4
7
7
4
- PA
- PB
, PC
PC
PC
PC
PC
PC
PC
INTR
INTR
OBF
ACK
1/0
STB
D
IBF
0
7
6
3
5
0
2
1
0
I/O
I/O
3
A
B
A
B
8
2
8
B
A
Selection of I/O
of PC
when not defined
as a control pin.
D
1
OBF
ACK
INTR
I/O
STB
IBF
INTR
2
1 = Input
0 = Output
4
B
and PC
A
B
A
A
B
D
Group A: Output
1
1
Group B: Input
Group A: Mode 1 Output
Group B: Mode 1 Input
5
D
INTR
INTR
¥
STB
ACK
OBF
IBF
0
MSM82C55A-2RS/GS/VJS
I/O
I/O
B
B
A
A
B
A
As all of PC
become a control pin
in this case, this bit is
"Don't Care".
Group A: Output
Group B: Output
0
- PC
INTR
INTR
3
OBF
ACK
ACK
OBF
I/O
I/O
bits
B
B
A
A
B
A
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