5.1 Sync PCI Triggering Configuration

The PG's main inter-instance triggering mechanism, PGTRGOUT, is only available within the PWM or APWM peripheral and is not cross-linked. In this application, both the PWM and APWM need to work together and share triggers. To do this, the Sync PCI blocks are utilized. The PCI blocks allow synchronization of external and asynchronous events into the PWM domain.

The ‘Sync’ instance of a PG’s PCI is the only instance type that can initiate a SOC trigger. The PG’s SOCS is configured to use its PCI block instead of being self-triggered or triggered from another PG (PGTRGOUT). The Sync PCI configuration is the same for the PGs in phases 2 and 3. There are three PWMEVTs available to each PCI block; however, the system needs to use four, as shown in Figure 5-1. To map the fourth, the PWMEVTD signal is routed through a virtual device pin and then into the PCI. The PCI configuration does not use an acceptance qualifier, and the acceptance logic is rising edge, auto-terminate.