TMS320F28377S: ADC Architecture and Input Signal Mapping

Hi Andrew,

These are exclusive physical channel connections for each ADC and you cannot reassign these to the other ADC modules. ADCIN14 and ADCIN15 are common channels that have direct connection to both ADC modules.

Regards,
Joseph

Thanks Joseph.

For ADC-A, do I only need to initialize ADCSOC0CTL - ADCSOC5CTL, and can I only program the CHSEL field with vales 0 - 5, corresponding to ADCINA0 - ADCINA5?

Likewise for ADC-B, do I only need to initialize ADCSOC0CTL - ADCSOC5CTL, and can I only program the CHSEL field with vales 0 - 5, corresponding to ADCINB0 - ADCINB5, or do I use 7 - 12?

ADCIN14 and ADCIN15 can be assigned to either ADC, with CHSEL fields being 14 (0xE) or 15 (0xF), correct?

Hi Andrew,

For either ADC module, you can use all SOCs from 0-15. Note that SOCs are not exclusively mapped to channels. You can map an SOC to any available channel that is available to the device. Most importantly, you need to be aware of the SOC trigger sequence. When SOC priority is not configured, conversion is initiated first on SOC0, then SOC1...and so forth until SOC15 or until SW tells it to stop depending on how you define and use the ADC interrupts.

For example, you can have an ADCA setup that assigns the channels as follows:

AdcaRegs.ADCSOC0CTL.bit.CHSEL = 3;
AdcaRegs.ADCSOC1CTL.bit.CHSEL = 1;
AdcaRegs.ADCSOC2CTL.bit.CHSEL = 2;
AdcaRegs.ADCSOC3CTL.bit.CHSEL = 5;
AdcaRegs.ADCSOC4CTL.bit.CHSEL = 0;
AdcaRegs.ADCSOC5CTL.bit.CHSEL = 15;
AdcaRegs.ADCSOC6CTL.bit.CHSEL = 14;
:
:

This set up is valid and the order of conversion will follow the SOC sequence and would convert on the corresponding channels assigned for each of the SOCs. Similar setup can be done on ADCB. You can even use only one SOC if that is all that your application requires.

Hope this clarifies the SOC/channel assignment for you.

Best regards,
Joseph

Mostly clarified, thanks.

One outstanding question, for programming of CHSEL for ADC-B: which is correct:

AdcbRegs.ADCSOC0CTL.bit.CHSEL = 0; // 0 corresponds to ADCINB0
AdcbRegs.ADCSOC1CTL.bit.CHSEL = 1; // 1 corresponds to ADCINB1
AdcbRegs.ADCSOC2CTL.bit.CHSEL = 2; // 2 corresponds to ADCINB2
AdcbRegs.ADCSOC3CTL.bit.CHSEL = 3; // 3 corresponds to ADCINB3
AdcbRegs.ADCSOC4CTL.bit.CHSEL = 4; // 4 corresponds to ADCINB4
AdcbRegs.ADCSOC4CTL.bit.CHSEL = 5; // 5 corresponds to ADCINB5

or this:
AdcbRegs.ADCSOC0CTL.bit.CHSEL = 6; // 6 corresponds to ADCINB0
AdcbRegs.ADCSOC1CTL.bit.CHSEL = 7; // 7 corresponds to ADCINB1
AdcbRegs.ADCSOC2CTL.bit.CHSEL = 8; // 8 corresponds to ADCINB2
AdcbRegs.ADCSOC3CTL.bit.CHSEL = 9; // 9 corresponds to ADCINB3
AdcbRegs.ADCSOC4CTL.bit.CHSEL = 10; // 10 corresponds to ADCINB4
AdcbRegs.ADCSOC4CTL.bit.CHSEL = 11; // 11 corresponds to ADCINB5

Many Thanks!!

Hi Andrew,

      Use the first set up since there are no physical channels for ADCB 6 to 11.

Regards,

Joseph