SPRUHX5I August 2014 – May 2024 TMS320F28374S , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378S , TMS320F28379S
The HRPWM is based on micro-edge positioner (MEP) technology. MEP logic is capable of positioning an edge very finely by sub-dividing one coarse system clock of a conventional PWM generator. The time step accuracy is on the order of 150ps. See the device data sheet for the typical MEP step size on a particular device. The HRPWM also has a self-check software diagnostics mode to check if the MEP logic is running as designed under all operating conditions. Details on software diagnostics and functions are in Section 14.14.1.7.
Figure 14-81 shows the relationship between one coarse system clock and edge position in terms of MEP steps, which are controlled using an 8-bit field in the Compare A extension register (CMPAHR). The same operating logic applies to CMPBHR as well.
To generate an HRPWM waveform, configure the ePWM registers to generate a conventional PWM of a given frequency and polarity. The HRPWM works together with the ePWM registers to extend edge resolution. Although many programming combinations are possible, only a few are needed and practical. These methods are described in Section 14.14.1.8.