The micro edge positioner (MEP) logic in HRPWM is capable of placing an edge in one of 255 discrete time steps. The size of these steps is of the order of 150 ps. For typical MEP step size, see the device-specific data sheet. The MEP step size varies based on worst-case process parameters, operating temperature, and voltage. MEP step size increases with decreasing voltage and increasing temperature and decreases with increasing voltage and decreasing temperature. Applications that use the HRPWM feature should use the TI-supplied MEP scale factor optimization (SFO) software function. The SFO function helps to dynamically determine the number of MEP steps per EPWMCLK period while the HRPWM is in operation.

The HRPWM module has built in self-check and diagnostic capabilities that can be used to determine the optimum MEP scale factor value for any operating condition. TI provides a C-callable library containing one SFO function that utilizes this hardware and determines the optimum MEP scale factor. For a given System Clock frequency at a given temperature, a known MEP scale factor value is returned by the SFO determination function. Proper System Clock frequency operation is verified by comparing the MEP scale factor value returned with the expected value.