Rev. 1.0, 02/00, page 361 of 1141
Section 18 8-Bit PWM
18.1
Overview
The 8-bit PWM incorporates 4 channels of the duty control method. Its outputs can be used to
control a reel motor or loading motor.
18.1.1
Features
•
Conversion period: 256-state
•
Duty control method
18.1.2
Block Diagram
Figure 18.1 shows a block diagram of the 8-bit PWM (1 channel).
PWMn
(n=3 to 0)
2
0
2
7
OVF
Match signal
[Legend]
PWRn
φ
PW8CR
: 8-bit PWM data register n
: 8-bit PWM control register
PWMn
OVF
: 8-bit PWM square-wave output pin n
: Overflow signal from FRC lower 8-bit
PWRn
Free-running counter (FRC)
Comparator
PW8CR
Polarity
specification
Internal data bus
R
S
Q
Figure 18.1 Block Diagram of 8-Bit PWM (1 channel)