38.3.4.1 Trigger Selection Class 2 Inputs

For each one of the Class 2 inputs, the user application can independently specify a conversion trigger source. The individual trigger source for an analog input ‘x’ is specified by the TRGSRC[4:0] bits located in registers ADCTRG1 through ADCTRG3. For example, these trigger sources may include:

  • General Purpose (GP) Timers: When a period match occurs for the 32-bit timer, Timer3/2 or Timer5/4, or the 16-bit Timer1, Timer3 or Timer5, a special ADC trigger event signal is generated by the timer. This feature does not exist for other timers. For more information, see Timer/Counter (TC) from Related Links.
  • Output Compare: The Output Compare peripherals, OC1, OC3 and OC5, can be used to generate an ADC trigger, then the output transitions from a low to high state. For more information, see Timer/Counter (TC) from Related Links.
  • Comparators: The analog Comparators can be used to generate an ADC trigger when the output transitions from a low state to a high state. For more information, see Digital Comparator from Related Links.
  • External INT0 Pin Trigger: In this mode, the ADC module starts a conversion on an active transition on the INT0 pin. The INT0 pin may be programmed for either a rising edge input or a falling edge input to trigger the conversion process.
  • Global Software Trigger: The ADC module can be configured for manually triggering a conversion for all inputs that have selected this trigger option. The user can manually trigger a conversion by setting the Global Software Trigger bit, GSWTRG (ADCCON3[6]).