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Original question:

CCS/TMS320F28069M: LAUNCHXL-F28069: Cannot rebuild and reload Demo from Code Composer v6

TMS320F28379D: Do timing events of one ADC module have an effect on the timing event of the other 3 ADC Modules

John Tsinetakes1
Intellectual 290 points

Part Number: TMS320F28379D

Question using the ADC on the Delfino F28379D LaunchPad and the C2000 DPS BoosterPack

 

 

 

 

   

If I am measuring three signals listed below at two different trigger location as shown below and the last signal Voltage Vin which is connected to a different ADC Module (Module B) compared to the other 4 measurements at Module C, does it matter what trigger number is assigned to the only measurement in ADC module B?

Can the signal Voltage Vin at ADC Module B ADCIN4 also be assigned SOC Trigger SOC1?

 

Since ADC Module C and ADC Module B are independent will the timing of the signal to ADC Module B have any effect on the timing of the signals measured at ADC Module C?

 

I read through SPRUHM8I TMS320F2837xD Dual-Core Microcontrollers Technical Reference Manual but it was not able to definitively determine if the independence of the ADC Modules meant then the timing events of one ADC module have no effect on the timing event of the other 3 ADC Modules.

 

 

 

 

  • 0
    TI__Guru 60865 points

    Hi John,

    It doesn't look like your images uploaded.

    Overall, the ADC modules can operate completely independently.  Triggering ADC-B only will result in only ADC-B converting.  There are no HW interlocks to force multiple ADCs to operate together.

    However, the typical use case is to setup multiple ADCs in parallel such that a single HW trigger will cause multiple ADCs to convert in parallel with identical timings. 

    Note that in the case of 12-bit ADCs, there is some performance degradation if the multiple ADCs are operating at the same time, but asynchronously.  In the case of 16-bit ADCs, operating asynchronously could cause significant performance degradation.  See the ENOB and ADC-to-ADC isolation specifications in the datasheet and the "Ensuring Synchronous Operation" section of the TRM.    

  • 0
    TI__Mastermind 43520 points

    Hi John,

    There is a section in TRM under Basic Synchronous Operation that discusses synchronous and asynchronous operation of multiple ADCs.  This is probably a good place to start.  Basic premise of this section is that as long as the ACQPS of all SOCs are equal, all ADC module clocks are the equal and triggers to the ADC modules are in sync, then simultaneous ADC operation is in synchronous mode, and is synchronous mode, the ADC conversions from other modules should not impact the others.  If the synchronous criteria is not met, then simultaneous ADC module conversion results will be degraded.  The datasheet provides these degradation numbers when ADCs are operating asynchronously.

    Regards,

    Joseph

  • 0 in reply to Joseph Casuga
    TI__Mastermind 43520 points

    Hi John,

    Did the TRM section Basic Synchronous Operation in the ADC chapter answer your concerns on multiple ADC operation?

    Regards,

    joseph