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¡ Semiconductor

MSM82C53-2RS/GS/JS

DESCRIPTION OF PIN FUNCTIONS

SYSTEM INTERFACING

16 bits

Address Bus

Control Bus

CS

8 bits

RD

WR

8 bits

Data Bus

MSM82C53-2

OUT GATE CLK

Counter #0

OUT GATE CLK

Counter #1

OUT GATE CLK

Counter #2

Pin Symbol

Function

Name

Three-state 8-bit bidirectional data bus used when writing control words

and count values, and reading count values upon reception of WR and

RD signals from CPU.

Bidirectional

Data Bus

Input/Output

One of the three internal counters or the control word register is selected

lower order bits of the address bus.

Address Input

Input

RD

Data can be transferred from MSM82C53-2 to CPU when this pin is at low

level.

Read Input

Input

WR

Data can be transferred from CPU to MSM82C53-2 when this pin is at low

level.

Write Input

Input

Supply of three clock signals to the three counters incorporated in

MSM82C53-2.

Clock Input

Input

Control of starting, interruption, and restarting of counting in the three

respective counters in accordance with the set control word contents.

Gate Input

Input

Output of counter output waveform in accordance with the set mode and

count value.

Counter Output

Output

CS

Data transfer with the CPU is enabled when this pin is at low level. When

state where neither writing nor reading can be executed. Internal registers,

however, remain unchanged.

Chip Select

Input

Input

Input/Output