Figure 144. Center-Aligned Pwm Waveforms (Arr=8) - ST STM32F207 Series Reference Manual

RM0033
up and down depending on the CMS bits configuration. The direction bit (DIR) in the
TIMx_CR1 register is updated by hardware and must not be changed by software. Refer to
Center-aligned mode (up/down
Figure 144
•
TIMx_ARR=8,
•
PWM mode is the PWM mode 1,
•
The flag is set when the counter counts down corresponding to the center-aligned
mode 1 selected for CMS=01 in TIMx_CR1 register.
Counter register
CCRx = 4
CCRx = 7
CCRx = 8
CCRx > 8
CCRx = 0
Hints on using center-aligned mode:
• When starting in center-aligned mode, the current up-down configuration is used. It
means that the counter counts up or down depending on the value written in the DIR bit
counting).
shows some center-aligned PWM waveforms in an example where:

Figure 144. Center-aligned PWM waveforms (ARR=8)

0 1 2
OCxREF
CMS=01
CCxIF
CMS=10
CMS=11
OCxREF
CMS=10 or 11
CCxIF
'1'
OCxREF
CMS=01
CCxIF
CMS=10
CMS=11
'1'
OCxREF
CMS=01
CCxIF
CMS=10
CMS=11
'0'
OCxREF
CMS=01
CCxIF
CMS=10
CMS=11
General-purpose timers (TIM2 to TIM5)
3 4 5 6 7 8
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7 6 5 4 3 2 1 0 1
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