ST10R272L - GENERAL PURPOSE TIMER UNITS
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negative transition of T3OTL. With this combination the core timer is alternately reloaded
from the two auxiliary timers.
The figure below shows an example for the generation of a PWM signal using the alternate
reload mechanism. T2 defines the high time of the PWM signal (reloaded on positive
transitions) and T4 defines the low time of the PWM signal (reloaded on negative
transitions). The PWM signal can be output on T3OUT with T3OE=‘1’, P3.3=‘1’ and
DP3.3=‘1’. With this method the high and low time of the PWM signal can be varied in a wide
range.
Note
The output toggle latch T3OTL is software accessible and may be changed, if
required, to modify the PWM signal. However, this will NOT trigger the reload of T3.
Note
Avoid selecting the same reload trigger event for both auxiliary timers as both
reload registers would try to load the core timer at the same time. If this
combination is selected, T2 is disregarded and the contents of T4 is reloaded.
Figure 80 GPT1 timer reload configuration for PWM generation
