Figure 6.7-13 Pwm Prescale Waveform In Up Count Type; Figure 6.7-14 Pwm Up Count Type - Nuvoton ISD94124BYI Technical Reference Manual

Figure 6.7-13 PWM Prescale Waveform in Up Count Type

6.7.6.2 PWM Counter
PWM supports three counter types operation: up count, down count and up-down count types.
6.7.6.3 Up Count Type
When PWM counter is set to up count type, CNTTYPE (TIMERx_PWMCTL[2:1]) is 0x0, it starts
up-counting from zero to PERIOD (TIMERx_PWMPERIOD[15:0]). The current counter value can
be read from the CNT (TIMERx_PWMCNT[15:0]). PWM generates a zero point event when both
counter and prescale counts to 0. PWM generates a period point event when the counter counts to
PERIOD and prescale counts to 0. Figure 6.7-14 shows an example of PWM up count type, where
PWM period time is (PERIOD+1) * (CLKPSC+1) * TMRx_PWMCLK.
PWMCNT
(TIMERx_PWMCNT[15:0])
PWMCNTEN
(TIMERx_PWMCTL[0])
zero point event
period point event
6.7.6.4 Down Count Type
When PWM counter is set to down count type, CNTTYPE (TIMERx_PWMCTL[2:1]) is 0x1, it starts
down-counting from PERIOD to zero, current counter value can be read from CNT
(TIMERx_PWMCNT[15:0]). PWM generates a zero point event when both counter and prescale
counts to 0. PWM generates a period point event when the counter counts to PERIOD and prescale
counts to 0. Figure 6.7-15 is an example of PWM down count type, where PWM period time is
(PERIOD+1) * (CLKPSC+1) * TMRx_PWMCLK.
Sep 9, 2019
ISD94100 Series Technical Reference Manual
PERIOD = 5 PERIOD = 8
5
4
3
2 2
1 1
0 0
PWM Period PWM Period

Figure 6.7-14 PWM Up Count Type

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