SPRUHM9H October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
The action-qualifier submodule operation is shown in Figure 14-21 and monitored by way of the registers in Section 14.15.
For convenience, the possible input events are summarized again in Table 14-3.
Signal | Description | Registers Compared |
---|---|---|
CTR = PRD | Time-base counter equal to the period value | TBCTR = TBPRD |
CTR = Zero | Time-base counter equal to 0 | TBCTR = 0x00 |
CTR = CMPA | Time-base counter equal to the counter-compare A | TBCTR = CMPA |
CTR = CMPB | Time-base counter equal to the counter-compare B | TBCTR = CMPB |
T1 event | Based on comparator, trip, or syncin events | None |
T2 event | Based on comparator, trip, or syncin events | None |
Software forced event | Asynchronous event initiated by software |
The software forced action is a useful asynchronous event. This control is handled by the AQSFRC and AQCSFRC registers.
The action-qualifier submodule controls how the two outputs EPWMxA and EPWMxB behave when a particular event occurs. The event inputs to the action-qualifier submodule are further qualified by the counter direction (up or down). This allows for independent action on outputs on both the count-up and count-down phases.
The possible actions imposed on outputs EPWMxA and EPWMxB are:
Actions are specified independently for either output (EPWMxA or EPWMxB). Any or all events can be configured to generate actions on a given output. For example, both CTR = CMPA and CTR = CMPB can operate on output EPWMxA. All qualifier actions are configured using the control registers found in the ePWM Registers section.
For clarity, the illustrations in this chapter use a set of symbolic actions. These symbols are summarized in Figure 14-22. Each symbol represents an action as a marker in time. Some actions are fixed in time (zero and period) while the CMPA and CMPB actions are moveable and the time positions are programmed by way of the counter-compare A and B registers, respectively. To turn off or disable an action, use the "Do Nothing option"(the default at reset).
The Action Qualifier Trigger Event Source Selection register (AQTSRCSEL) is used to select the source for T1 and T2 events. T1/T2 selection and configuration of a trip/digital-compare event in Action Qualifier submodule is independent of the configuration of that event in the Trip-Zone submodule. A particular trip event can or cannot be configured to cause trip action in the Trip Zone submodule, but the same event can be used by the Action Qualifier to generate T1/T2 for controlling PWM generation.