Figure 6.8-7 Pwm0 Counter Waveform When Set Clear Counter; Figure 6.8-8 Pwm Up Counter Type - Nuvoton ISD94124BYI Technical Reference Manual

6.8.5.2 PWM Counter
PWM supports 3 counter types operation: Up Counter, Down Counter and Up-Down Counter types.
For PWM channel0, CNT(PWM_CNT0[15:0]) can clear to 0x00 by CNTCLR0 (PWM_CNTCLR[0]).
CNT will be cleared when prescale counter to 0, and CNTCLR will be set 0 by hardware
automatically.
PCLK
PWM0_CLK
CNTCLR0
(PWM_CNTCLR[0])
CNTEN0
(PWM_CNTEN[0])
Prescale counter
CNT
(PWM_CNT0[15:0])

Figure 6.8-7 PWM0 Counter Waveform when set clear counter

6.8.5.3 Up Counter Type
When PWM counter is set to up counter type, CNTTYPEn (PWM_CTL1[2n+1:2n], n = 0,1..5) is
0x0, it starts up-counting from zero to PERIOD (PWM_PERIODn[15:0], where n denotes channel
number) to complete a PWM period. The current counter value can be read from CNT
(PWM_CNTn[15:0]) bits. PWM generates zero point event when the counter counts to 0 and
prescale counts to 0. PWM generates period point event when the counter counts to PERIOD and
prescale counts to 0. The Figure 6.8-8 shows an example of up counter, wherein
PWM period time = (PERIOD+1) *(CLKPSC+1)* PWM0_CLK.
CNT
(PWM_CNTn[15:0])
CNTENn
(PWM_CNTEN[n])
zero point event
period point event
Note: n denotes channel 0,1..5
Sep 9, 2019
ISD94100 Series Technical Reference Manual
0 4 3 2 1 0 4 3 2 1 0
x 0
PERIOD = 5 PERIOD = 8
5
4
3 3
2 2
1 1
X 0 0
PWM Period PWM Period

Figure 6.8-8 PWM Up Counter Type

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3 2 1 0 4
4 3 2 1 0 4 3 2 1 0 4
2
1
PERIOD = 8
8
7
6
5 5
4 4
3
2
1
0
PWM Period
3 2
0 1
8
7
6
2
1
0
Rev1.09