SPRUHM9H October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
If only one trigger source is used, one ADC can use more SOCs than the other ADCs while still operating synchronously.
Example: Synchronous Operation With Uneven SOC Numbers
AdcaRegs.ADCSOC0CTL.bit.CHSEL = 4; //SOC0 converts ADCINA4
AdcaRegs.ADCSOC0CTL.bit.ACQPS = 19; //SOC0 uses sample duration of 20 SYSCLK cycles
AdcaRegs.ADCSOC0CTL.bit.TRIGSEL = 10; //SOC0 begins conversion on ePWM3 SOCB
AdcbRegs.ADCSOC0CTL.bit.CHSEL = 0; //SOC0 converts ADCINB0
AdcbRegs.ADCSOC0CTL.bit.ACQPS = 19; //SOC0 uses sample duration of 20 SYSCLK cycles
AdcbRegs.ADCSOC0CTL.bit.TRIGSEL = 10; //SOC0 begins conversion on ePWM3 SOCB
AdcaRegs.ADCSOC1CTL.bit.CHSEL = 4; //SOC1 converts ADCINA4
AdcaRegs.ADCSOC1CTL.bit.ACQPS = 30; //SOC1 uses sample duration of 31 SYSCLK cycles
AdcaRegs.ADCSOC1CTL.bit.TRIGSEL = 10; //SOC1 begins conversion on ePWM3 SOCB
AdcbRegs.ADCSOC1CTL.bit.CHSEL = 1; //SOC1 converts ADCINB1
AdcbRegs.ADCSOC1CTL.bit.ACQPS = 30; //SOC1 uses sample duration of 31 SYSCLK cycles
AdcbRegs.ADCSOC1CTL.bit.TRIGSEL = 10; //SOC1 begins conversion on ePWM3 SOCB
AdcaRegs.ADCSOC2CTL.bit.CHSEL = 0; //SOC2 converts ADCINA0
AdcaRegs.ADCSOC2CTL.bit.ACQPS = 19; //SOC2 uses sample duration of 20 SYSCLK cycles
AdcaRegs.ADCSOC2CTL.bit.TRIGSEL = 10; //SOC2 begins conversion on ePWM3 SOCB
Note that if the trigger comes again before all SOCs have completed the conversions, ADCB begins converting immediately on SOC0 while ADCA does not start converting SOC0 again until SOC2 is complete. This results in asynchronous operation, so care must be taken to not overflow the trigger.