msm82c55a-2gs Oki Semiconductor, msm82c55a-2gs Datasheet - Page 11

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

¡ Semiconductor
OPERATIONAL DESCRIPTION
Control Logic
Operations by addresses and control signals, e.g., read and write, etc. are as shown in the table
below:
Setting of Control Word
The control register is composed of 7-bit latch circuit and 1-bit flag as shown below.
Operaiton
Output
Control
Others
Input
D
7
A
0
0
1
0
0
1
1
1
¥
1
D
Group A Control Bits
6
Control word Identification flag
Be sure to set 1 for the control word
to define a mode and input/output.
A
0
1
0
0
1
0
1
1
¥
D
0
5
When set to 0, it becomes
the control word for bit set/
reset.
CS
D
0
0
0
0
0
0
0
0
1
4
D
WR
¥
3
1
1
1
0
0
0
0
1
D
Group B Control Bits
2
RD
0
0
0
1
1
1
1
0
¥
D
1
Data Bus Æ Port C
Port A Æ Data Bus
Port B Æ Data Bus
Data Bus Æ Port A
Data Bus Æ Port B
Data Bus Æ Control Register
Illegal Condition
Port C Æ Data Bus
Data bus is in the high impedance status.
D
0
Definition of input/
output of low order
4 bits of port C.
Definition of input/
output of 8 bits of
port B.
Mode definition of
group B.
Definition of input/
output of high order
4 bits of port C.
Definition of input/
output of 8 bits of
port A.
Mode definition of group A.
D
0
0
1
6
MSM82C55A-2RS/GS/VJS
Operation
D
0
1
¥
5
Mode 0
Mode 1
Mode 2
Mode
0 = Output
1 = Input
0 = Output
1 = Input
0 = Mode 0
1 = Mode 1
0 = Output
1 = Input
0 = Output
1 = Input
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