• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 83 subscribers
  • Views 438 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TMS320F28377D: can not generate PWM wave

nirvana_xun
Intellectual 535 points

Part Number: TMS320F28377D

i set the ePWM module in syscfg as following, but the ePWMxA stuck at low and the ePWMxB stuck at high, what is wrong with the configuration. how can i adapt it. DC, ET, chopper are not used here

d2cf9f61-e5b4-4a2b-bbee-18ac92bf8f8b.png

e9af3789-3e1e-407b-b5f3-edade711cc97.png

9453e9f5-0495-431a-8dee-5799227c3f40.png

14581e5c-4861-4427-927f-0a9404e801bd.png

9bf718defe3bc9f2627af3737ec30f0e.png

 

  • 0
    Intellectual 535 points

    when enable DB module in AHC mode and RED/FED input sources are both ePWMxA, the ePWMxA output low level and the ePWMxB output high level, it seems that ePWMxA stucks at low level, no matter how i set the AQ module, i just cannot change ePWMxA, why? and i read the tbctr and cmpA/B register, tbctr is counting up, cmpA and cmpB have non zero value, but  in the process it seems that the cmpA/B events do not occur once.

  • 0
    Intellectual 535 points

    i can only change the ePWMxA/B using ctr_prd/zro event, cmpA/B events seem not work, no matter what i set

  • 0 in reply to nirvana_xun
    Intellectual 535 points

    both epwmA and epwmB aqctl register using direct mode, but in the actual value of aqctl, these registers setting is shadow mode!! what is wrong

  • 0
    Intellectual 535 points

    when i totally use the syscfg for ePWM modules, the AQCTLA/B shadowmode is not set as the syscfg, AQCTL vaulue is 0x0050. so i manually change the shadow mode of ePWMxA/B action qualifier, by "EPwM_disableActionQualifierShadowLOadMOde(myEPWM INU2 U BASE, EPWM ACTION QUALIFIER A),
    EPWM_disableActionQualifierShadowLOadMOde(myEPWM INU2 U BASE, EPWM ACTION QUALIFIER B)," this change the AQCTL value but AQCTLA and AQCTLB turn into 0x0000, so i manually set the AQCTLA/B again. finally this setting works. Are there any bugs in the syscfg tools, it seems it does not work well.

  • 0 in reply to nirvana_xun
    TI__Expert 6100 points

    Please use the ePWM developer guide to configure the ePWM: https://www.ti.com/lit/an/sprad12a/sprad12a.pdf

    The guide above provides step by step guide to setup the ePWM.

    I see number of issue in your config:

    1. Your counter is freeze mode. you need to put it in either up mode, down mode or up-down mode.

    2. You need to provide finite CMPA value to have comparison. Calculation is shown in the guide. 

    3. Shadow mode need to be selected when loading CMPA.

    Also you can install C2000Ware and refer the example directly to compare your code with reference code. 

    Regards,

    Sumit