GD32E23x User Manual
247
Figure 14-15. Output-compare in three modes
CEN
CNT_REG
00
01
02
03
04
05
…
.
62
63
Overflow
match toggle
CNT_CLK
OxCPRE
00
01
02
03
04
05
…
.
62
63
01
02
03
04
05
…
.
00
match set
match clear
OxCPRE
OxCPRE
Output PWM function
In the output PWM function
(by setting the CHxCOMCTL bit to 3’b110 (PWM mode 0) or to
3’b 111(PWM mode 1)), the channel can generate PWM waveform according to the
TIMERx_CAR registers and TIMERx_CHxCV registers.
Based on the counter mode, PWM can also be divided into EAPWM (Edge-aligned PWM)
and CAPWM (Center-aligned PWM).
The
EAPWM’s period is determined by TIMERx_CAR and the duty cycle is determined by
TIMERx_CHxCV.
Figure 14-16. Timing chart of EAPWM
shows the EAPWM output and
interrupts waveform.
The
CAPWM’s period is determined by 2*TIMERx_CAR, and the duty cycle is determined by
2*TIMERx_CHxCV.
Figure 14-17. Timing chart of CAPWM
shows the CAPWM output and
interrupts waveform.
In up counting mode, if the value of TIMERx_CHxCV is greater than the value of
TIMERx_CAR, the output will be always inactive in PWM mode 0 (CHxCOMCTL=3’b110).
And if the value of TIMERx_CHxCV is greater than the value of TIMERx_CAR, the output will
be always active in PWM mode 1 (CHxCOMCTL=3’b111).