HRPWM - HRC Dead time insertion for HR and LR paths

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Hi all,

The following snippet left me a little confused about how exactly does dead time generation work inside HRC subunits and what is the reference clock (and, please, correct me if I am wrong - "reference clock" is the name for CCU module clock whenever it is referred to throughout the chapter. For the sake of being descriptive I called HR path clock a reference clock for DT generator) for DT in HR signals? Here is the snippet itself:

The Low Resolution Path, only generates one dead time counter clock, due to the fact that the signals generated via this path are always aligned with the reference clock (no high resolution adjustment).

The High Resolution Path, generates two dead time counter clocks. One clock aligned with the High Resolution Set and another aligned with the High Resolution Clear signal, Figure 22-82.


The timing diagrams afterwards show the following:

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Which shows that the dead time is "set" (if enabled) with the HRPWM clock that is phase shifted, but is aligned with the reference/module coarse clock. This is totally understandable, however, what confused me is the snippet from the reference manual. What exactly does it mean that the HR path has two clocks that are aligned with Set and Clear signals? And if this means exactly what the diagram shows - then how is the Low Resolution path dead time clock different?

Regards,
Andrey
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Hi all,

After reviewing this section of the reference manual I think I finally understand this idea. In short, high resolution path allows for different clock shifting on rising and falling edges. Due to this the delay on the two deadband signals can be different - since dead time insertion occurs when output signal changes states, then the moment the dead time is triggered will be aligned with an edge, which is in turn positioned by the high resolution channel (HRC). The low resolution channel, however, only has a single clock (coarse reference clock) that it can pass to the dead time generator, and the moment in time that the deadband is triggered will be aligned with the coarse clock for both rising and falling edge, even though the dead time may still change (i.e. 1, 2, 3, ... clock counts), just like in CCU module.

Regards,
Andrey
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