Problems in TMS570LC4357 ADC conversion

How is group1 triggered? You may want to toggle an I/O pin at the code which generates the trigger to see if there is anything missing in the software.

Thanks and regards,

Zhaohong

Hi Zhaohong,

Thanks for your reply!

The group 1 was hardware-triggered. The adc file was generated by Halcogen. The thing is both Event Group and Group 1 settings are the same (adcREG1->EVSRC and adcREG1->G1SRC), then how come ADC in Event group is working while the Group 1 is not?

Here are my settings:

 /** - Setup event group conversion mode
    *     - Setup data format
    *     - Enable/Disable channel id in conversion result
    *     - Enable/Disable continuous conversion
    */
    adcREG1->GxMODECR[0U] = (uint32)ADC_12_BIT
                          | (uint32)0x00000000U
                          | (uint32)0x00000000U;

    /** - Setup event group hardware trigger
     *     - Setup hardware trigger edge
     *     - Setup hardware trigger source
     */
    adcREG1->EVSRC = (uint32)0x00000008U
                   | (uint32)ADC1_EPWM_B;

    /** - Setup event group sample window */
    adcREG1->EVSAMP = 0U;

    /** - Setup event group sample discharge
    *     - Setup discharge prescaler
    *     - Enable/Disable discharge
    */
    adcREG1->EVSAMPDISEN = (uint32)((uint32)0U << 8U)
                         | (uint32)0x00000000U;

    /** - Setup group 1 conversion mode
    *     - Setup data format
    *     - Enable/Disable channel id in conversion result
    *     - Enable/Disable continuous conversion
    */
    adcREG1->GxMODECR[1U] = (uint32)ADC_12_BIT
                          | (uint32)0x00000000U
                          | (uint32)0x00000008U
                          | (uint32)0x00000000U;

    /** - Setup group 1 hardware trigger
     *     - Setup hardware trigger edge
     *     - Setup hardware trigger source
     */
    adcREG1->G1SRC = (uint32)0x00000008U
                   | (uint32)ADC1_EPWM_B; /* Alternate Trigger Source */

    /** - Setup group 1 sample window */
    adcREG1->G1SAMP = 0U;

    /** - Setup group 1 sample discharge
    *     - Setup discharge prescaler
    *     - Enable/Disable discharge
    */
    adcREG1->G1SAMPDISEN = (uint32)((uint32)0U << 8U)
                         | (uint32)0x00000000U;

Thanks a lot!!

Yue

Zhaohong Zhang said:

How is group1 triggered? You may want to toggle an I/O pin at the code which generates the trigger to see if there is anything missing in the software.

Thanks and regards,

Zhaohong

Hi Sunil,

Thanks for your answer.
Yes, there is sufficient time between the two sets of conversions, otherwise group1 of ADC would not work when I loaded the code and ran it. Now, the issue that I am facing is : When I loaded the code into the board and ran it immediately, it worked great! However, after I power-cycled the board, only event group of ADC was still working but the group 1 ADC was not.....that means,group 1 of ADC worked fine unless I power-cycled the board. BTW, event group was never affected by the power-cycling the board.

Maybe it was trigger issue (?) I am checking it now but event group and group 1 have the same trigger settings, how come the ADC conversion in group 1 is not working when the board is power-cycled??

Thanks, again!

yue

There is something missing in your software. I would suggest you disabling the event group and only enable group 1 and observe the behavior.

Thanks and regards,

Zhaohong

Hi Zhaohong,

I disabled "event group" by "deselecting" the channels in event group. Now, only group1's channels are selected.

I can see clearly that ADC results from event group don't work, which is true since no channels there were selected. But, for group 1, it is the same as before, when I loaded the code and ran it immediately, it was working fine; after I power-cycled the board, group 1 didn't work....

Thanks!

Yue

Hi Sunil,

I read your post again and the ref manual. I think I might be closer to the reason. Firstly, in my code, the Event group was hardware triggered by ADC1_EPWM_B. The Group 1 was software- triggered and alternate trigger is hardware trigger which was also ADC1_EPWM_B.
When I loaded the code and ran it, the software-trigger for my group1 was working fine. But, when I power-cycled the board, for some reason, the software-trigger for Group1 was not working. Then, the alternate hardware trigger kicked in, that is ADC1_EPWM_B. Now, the event group and group 1 share the same hardware trigger. Since the event group has higher priority as you said, whenever the ADC1_EPWM_B came, the even group'd work but the group 1 could not be executed.

If my thinking is correct, I could either fixed the software trigger in my code or has new hardware-trigger for group 1 (?)