msm82c55a-2gs Oki Semiconductor, msm82c55a-2gs Datasheet - Page 19

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

¡ Semiconductor
4. When Group A is Different in Mode from Group B
(Mode combinations that define no control bit at port C)
6
8
1
2
3
4
5
7
9
Group A and group B can be used by setting them in different modes each other at the same
time. When either group is set to mode 1 or mode 2, it is possible to set the one not defined
as a control pin in port C to both input and output as port which operates in mode 0 at the
3rd and 0th bits of the control word.
When the I/O bit is set to input in this case, it is possible to access data by the normal port
C read operation.
When set to output, PC
Meanwhile, 3 bits from PC
The bit set/reset function can be used for all of PC
varies according to the combination of modes like this.
Group A
Mode 1
Mode 0
Mode 0
Mode 0
Mode 1
Mode 1
Mode 1
Mode 2
Mode 1
Output
Output
Output
Input
input
Input
Group B
Mode 1
Mode 1
Mode 1
Mode 0
Mode 0
Mode 0
Mode 1
Mode 1
Mode 1
Output
Output
Output
Input
Input
Input
OBF
OBF
OBF
OBF
7
PC
I/O
I/O
I/O
I/O
I/O
-PC
Controlled at the 3rd bit (D
A
A
A
A
2
7
4
to PC
bits can be accessed by the bit set/reset function only.
ACK
the Control Word
ACK
ACK
ACK
PC
I/O
I/O
I/O
I/O
I/O
0
6
A
A
A
A
can be accessed by normal write operation.
PC
IBF
IBF
IBF
IBF
I/O
I/O
I/O
I/O
I/O
5
A
A
A
A
3
) of
STB
STB
STB
STB
PC
3
I/O
I/O
I/O
I/O
I/O
-PC
4
A
A
A
A
Port C
0
bits. Note that the status of port C
INTR
INTR
INTR
INTR
INTR
INTR
INTR
PC
I/O
I/O
Controlled at the 0th bit (D
3
A
A
A
A
MSM82C55A-2RS/GS/VJS
A
A
A
the Control Word
ACK
STB
STB
ACK
STB
ACK
PC
I/O
I/O
I/O
B
B
2
B
B
B
B
OBF
OBF
OBF
IBF
PC
IBF
IBF
I/O
I/O
I/O
B
B
B
B
1
B
B
0
) of
INTR
INTR
INTR
INTR
INTR
INTR
19/26
PC
I/O
I/O
I/O
0
B
B
B
B
B
B