M38503M4H Datasheet, PDF (30/51 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

b7
b0
PWM control register
(PWMCON : address 001D16)
PWM function enable bit
0: PWM disabled
1: PWM enabled
Count source selection bit
0: f(XIN) (f(XCIN) at low-speed mode)
1: f(XIN)/2 (f(XCIN)/2 at low-speed mode)
Not used (return “0” when read)
Fig. 29 Structure of PWM control register
MITSUBISHI MICROCOMPUTERS
3850 Group (Spec. H)
SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER
PWM output
PWM register
write signal
B= C
A
B
C
T T2
T
T
T2
(Changes “H” term from “A” to “B”.)
PWM prescaler
write signal
(Changes PWM period from “T” to “T2”.)
When the contents of the PWM register or PWM prescaler have changed, the PWM
output will change from the next period after the change.
Fig. 30 PWM output timing when PWM register or PWM prescaler is changed
sNote
The PWM starts after the PWM function enable bit is set to enable and “L” level is output from the PWM pin.
The length of this “L” level output is as follows:
n+1
sec
2 • f(XIN)
(Count source selection bit = 0, where n is the value set in the prescaler)
n+1
sec (Count source selection bit = 1, where n is the value set in the prescaler)
f(XIN)
30