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Delfino ADC Interface

Michi Yama
Guru 10030 points

Other Parts Discussed in Thread: TMS320C28346

High,

I have an question regarding "EXTOSC" of Delfino for the exeternal OSC.

According to the section 4.7 "ADC Interface" in Delfino's data manual (SPRS516D),

The external ADC interface operation is configured, controlled, and
monitored by the External SoC Configuration Register (EXTSOCCFG) at address
0x702E. Figure 4-8 illustrates
how the Start-of-Conversion signals for external ADCs are generated by the
on-chip PWM modules.

What does the above sentence mean? Is ePWM module needed to use the external ADC? Also, if PWM setting is changed, is this mean ADC sampling rate changed?

I appreciate quick reply.

Best regards,

Michi

  • 0
    Guru 192875 points

    Hi Michi,

    The EXTSOCxA and EXTSOCxB and EXTADCCLK come out on dedicated pins.  These can be used to start an external ADC conversion.  The external ADC interface that configures these pins as shown in the diagram is controlled by the EXTSOCCFG register which is documented in the TMS320x2834x Delfino System Control and Interrupts Reference Guide (www.ti.com/lit/SPRUFN1).

    What does the above sentence mean?

    So what it means is, the PWM module in the mcu can trigger the external ADC and this configuration can be done in EXTSOCCFG.

    Is ePWM module needed to use the external ADC?

    If you want to trigger your external ADC conversion by mcu's PWM module then yes; ePWM module is required.

    Also, if PWM setting is changed, is this mean ADC sampling rate changed?

    Yes, the PWM period decides the sampling rate of ADC.

    Regards,

    Gautam

  • 0 in reply to Gautam Iyer
    Guru 10030 points

    Dear Gautam-san,

    Thank you for your quick reply.

    Please give me one more question.

    > If you want to trigger your external ADC conversion by mcu's PWM module then yes; ePWM module is required.

    What are other peripherals that can be used for ADC triggering? 

    Please let me know.

    Best regards,

    Michi

  • 0 in reply to Michi Yama
    Guru 192875 points

    What are other peripherals that can be used for ADC triggering?

    Which controller are you using?

  • 0 in reply to Gautam Iyer
    Guru 10030 points

    Gautam-san,

    Thank you for your quick reply.

    The controller is TMS320C28346.

    Best regards,

    Michi

     

  • 0 in reply to Michi Yama
    Guru 192875 points

    Michi-san,

    Fine, refer your external ADC datasheet for the other ways to trigger the SOC. If you're unable to find out, do share the ADC details.

    Regards,

    Gautam