UPD784020 Datasheet, PDF (34/90 Pages) NEC – 16/8-BIT SINGLE-CHIP MICROCOMPUTER

mPD784020, 784021
8.5 PWM OUTPUT (PWM0, PWM1)
Two channels of PWM (pulse width modulation) output circuitry with a resolution of 12 bits and a repetition
frequency of 48.8 kHz (fCLK = 12.5 MHz) are incorporated. Low or high active level can be selected for the PWM output
channels, independently of each other. This output is best suited to DC motor speed control.
Fig. 8-6 Block Diagram of PWM Output Unit
Internal bus
16
PWM modulo register
PWMn 15
87 43 0
8
PWM control register
(PWMC)
8
4
Reload
control
fCLK
Prescaler
8-bit
down-counter
1/256
Pulse control
circuit
4-bit counter
Output
control
PWMn (output pin)
Remark n = 0, 1
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