In a PWM modulator, the carrier generator, which is often based on a counter, must be executed inside a SCTL.
In this case, each execution results in a constant time step equals to a single clock pulse.
When it is executed outside a SCTL, you cannot control the time-step resulti, often, in a different switching/sampling frequency.
Moreover, you can use integer data type instead of FXP.
If you need higher PWM resolution, you can link the SCTL to a higher derived clock. I run my PWM modulator and its scheduler @ 120MHz.