One-Pulse Mode; Figure 152. Edge-Aligned Pwm Waveforms (Arr=8) - ST STM32F100 Series Reference Manual

General-purpose timers (TIM12/13/14)
TIMx_CCRx is greater than the auto-reload value (in TIMx_ARR) then OCxREF is held at
'1'. If the compare value is 0 then OCxRef is held at '0'.
aligned PWM waveforms in an example where TIMx_ARR=8.
CCRx=4
CCRx=8
CCRx>8
CCRx=0
14.3.10

One-pulse mode

One-pulse mode (OPM) is a particular case of the previous modes. It allows the counter to
be started in response to a stimulus and to generate a pulse with a programmable length
after a programmable delay.
Starting the counter can be controlled through the slave mode controller. Generating the
waveform can be done in output compare mode or PWM mode. Select One-pulse mode by
setting the OPM bit in the TIMx_CR1 register. This makes the counter stop automatically at
the next update event UEV.
A pulse can be correctly generated only if the compare value is different from the counter
initial value. Before starting (when the timer is waiting for the trigger), the configuration must
be as follows:
CNT < CCRx≤ ARR (in particular, 0 < CCRx)
358/709

Figure 152. Edge-aligned PWM waveforms (ARR=8)

0
Counter register
OCXREF
CCxIF
OCXREF
CCxIF
'1'
OCXREF
CCxIF
'0'
OCXREF
CCxIF
1 2 3 4 5
RM0041 Rev 6
Figure 152 shows some edge-
6 7 8 0
RM0041
1
MS31093V1