SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
A time-base synchronization scheme connects all of the EPWM modules on a device. Each EPWM module has a synchronization input (EPWMxSYNCI) and a synchronization output (EPWMxSYNCO). The input synchronization for the first instance (EPWM0) comes from an external pin. For the device EPWM environment sync pin details refer to EPWM Environment. The possible synchronization connections for the remaining EPWM modules is shown in Figure 12-180.
Each EPWM module can be configured to use or ignore the synchronization input. If the EPWM_TBCTL[2] PHSEN bit is set, then the time-base counter (TBCNT) of the EPWM module (EPWM_TBCNT register) will be automatically loaded with the phase register (EPWM_TBPHS) contents when one of the following conditions occur:
This feature enables the EPWM module to be automatically synchronized to the time base of another EPWM module. Lead or lag phase control can be added to the waveforms generated by different EPWM modules to synchronize them. In up-down-count mode, the EPWM_TBCTL[13] PHSDIR bit configures the direction of the time-base counter immediately after a synchronization event. The new direction is independent of the direction prior to the synchronization event. The TBPHS bit is ignored in count-up or count-down modes. See Figure 12-181 through Figure 12-184 for examples.
Clearing the EPWM_TBCTL[2] PHSEN bit configures the EPWM to ignore the synchronization input pulse. The synchronization pulse can still be allowed to flow-through to the EPWMxSYNCO and be used to synchronize other EPWM modules. In this way, a controller time-base (for example, EPWM1) and downstream modules (EPWM2–EPWMx) can be set and they may select to run in synchronization with the controller.