msm82c55a-2rs Oki Semiconductor, msm82c55a-2rs Datasheet - Page 10

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

¡ Semiconductor
BASIC FUNCTIONAL DESCRIPTION
Group A and Group B
When setting a mode to a port having 24 bits, set it by dividing it into two groups of 12 bits each.
Mode 0, 1, 2
There are 3 types of modes to be set by grouping as follows:
When used in mode 1 or mode 2, however, port C has bits to be defined as ports for control signal
for operation ports (port A for group A and port B for group B) of their respective groups.
Port A, B, C
The internal structure of 3 ports is as follows:
Single bit set/reset function for port C
When port C is defined as an output port, it is possible to set (to turn to high level) or reset (to
turn to low level) any one of 8 bits individually without affecting other bits.
Group A: Port A (8 bits) and high order 4 bits of port C (PC
Group B: Port B (8 bits) and low order 4 bits of port C (PC
Mode 0: Basic input operation/output operation (Available for both groups A and B)
Mode 1: Strobe input operation/output operation (Available for both groups A and B)
Mode 2: Bidirectional bus operation (Available for group A only)
Port A: One 8-bit data output latch/buffer and one 8-bit data input latch
Port B: One 8-bit data input/output latch/buffer and one 8-bit data input buffer
Port C: One 8-bit data output latch/buffer and one 8-bit data input buffer (no latch for input)
3
~PC
7
MSM82C55A-2RS/GS/VJS
~PC
0
)
4
)
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