One-Pulse Mode; Figure 189. Edge-Aligned Pwm Waveforms (Arr=8) - ST STM32F412 Reference Manual

RM0402
CCRx=4
CCRx=8
CCRx>8
CCRx=0
18.3.10

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. One-pulse mode is selected
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)

Figure 189. Edge-aligned PWM waveforms (ARR=8)

0
Counter register
OCXREF
CCxIF
OCXREF
CCxIF
OCXREF '1'
CCxIF
'0'
OCXREF
CCxIF
General-purpose timers (TIM9 to TIM14)
1 2 3 4 5
RM0402 Rev 6
6 7 8 0 1
MS31093V1
561/1163
591