It is worth looking at the C28x PWM generator in a little more detail, and with relevance to a specific application. On the left side of the slide is shown the internal structure of one PWM module. Each module consists of seven programmable sub-modules. Time-base and counter compare modules configure the basic PWM frequency and switching thresholds, while the action qualifier module assigns PWM edges to each comparator event. Programmable rising and falling edge dead-band may be added to the resulting PWM waveform. Finally, the trip zone sub-module determines PWM action in the event of a fault condition. In this way, the PWM module delivers two, highly flexible PWM outputs from a single time-base. Several such modules may be synchronised in a manner that the underlying time-bases may be shared or offset against one another, allowing multiple phase shifted PWM patterns to be constructed. In the timing diagram on the right, a typical waveform for a phase shifted full bridge power converter is shown. This topology uses the phase shift between two complementary pair PWM waveforms as the primary controlled variable. Modulation of dead-band is sometimes used to maintain the converter in an efficient “zero voltage switched” mode. Hardware interrupts and triggers for the A/D converter are also generated automatically by the event trigger sub-module as shown.