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Rev. 1.00
316 of 576
January 28, 2022
32-Bit Arm
®
Cortex
®
-M0+ MCU
HT32F54231/HT32F54241/HT32F54243/HT32F54253
15 Motor Control T
imer (MCTM)
Asymmetric PWM Mode
Asymmetric PWM mode allows two center-aligned PWM signals to be genetated with a
programmable phase shift. While the PWM frequency is determined by the value of the CRR
register, the duty cycle and the phase-shift are determined by the CHxCCR and CHxACR register.
When the counter is counting up, the PWM uses the value in CHxCCR as up-count compare value.
When the counter is in counting down stage, then the value in the CHxACR register is used as the
down-count compare value. The following figure is shown as an example for asymmetric PWM
mode in Center-aligned Counting mode.
Note: Asymmetric PWM mode can only be operated in Center-aligned Counting mode.
2 3 4 5 6 7
0 1
8
5 4 3 2 1 0
7 6
2 3 4 5 6 7
1
8
5 4 3 2 1 0
7 6
2 3 4 5 6 7
1
8
5 4 3 2 1
7 6
CNTR
CHxOREF
CHxOREF
CHxOREF
CHxOREF
PWM center-aligned mode
CRR = 8
CCR = 3, ACR = X
PWM center-aligned mode
CRR = 8
CCR = 5, ACR = X
Asymmetric PWM center-aligned mode
CRR = 8
CCR = 3, ACR = 5
Asymmetric PWM center-aligned mode
CRR = 8
CCR = 5, ACR = 3
CCR = 3
CCR = 5
CCR = 3
ACR = 5
CCR = 5
ACR = 3
Phase delay = 2
CRR = 8
Figure 110. Asymmetric PWM Mode versus Center-Aligned Counting Mode