M37517F8HP Datasheet, PDF (36/98 Pages) Renesas Technology Corp – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

7517 Group
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)
1: f(XIN)/2
Not used (return “0” when read)
Fig. 39 Structure of PWM control register
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. 40 PWM output timing when PWM register or PWM prescaler is changed
sNote
The PWM starts after the PWM 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)
Rev.1.01 Aug 02, 2004 page 36 of 96