• State TI Thinks Resolved
  • Locked Locked
  • Replies 4 replies
  • Answers 1 answer
  • Subscribers 82 subscribers
  • Views 645 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.

Original question:

TMS320F280037: What is EPWMCLK?

TMS320F280037: Relationship between EXTSYNCIN and EXTSYNCOUT

mokkun
Prodigy 550 points
Part Number: TMS320F280037


Tool/software:

TMS320F28003x TRM(spruiw9c.pdf) shows EXTSYNCIN1&2 go to "ePWM Sync Scheme" as follows.

Figure 20-3. ePWM Modules and Critical Internal Signal Interconnects

My question here is, How EXTSYNCIN is used to generate EXTSYNCOUT.

"20.4.3.3 Time-Base Counter Synchronization" mentions EXTSYNCIN1&2 but "Figure 20-7. Time-Base Counter Synchronization Scheme" does not show it.

Would you please help me to understand?

The following is just FYI, F28075 TRM (spruhm9h.pdf) mentions the relationship between EXTSYNCIN and EXTSYNCOUT very clearly as follows.

Regards,

  • 0
    TI__Prodigy 550 points

    Please excuse me to remind you that I am looking forward to support for this inquiry.

    Regards,

  • 0 in reply to mokkun
    TI__Intellectual 2297 points

    Hi Mokkun,

    Apologies for delayed response.

    The EXTSYNCIN is an external input mechanism is used to sync the TBCNTR in a given EPWM, along with the other EPWM SYNCOUT as well as ECAP SYNCOUT. The EXTSYNCOUT mechanism is used to send out the sync out signal from a given EPWM to external output.

    If you are looking to route the EXTSYNCIN to EXTSYNCOUT, please select any EPWM to sync with the EXTSYNCIN (via Inputxbar) and then the set it for syncout on an event from the EPWM.  Note that, this is not a direct relation from EXTSYNCIN to EXTSYNCOUT, rather an indirect way via a given EPWM.

    Please let me know if you need more information.

    Thanks and regards,

    Madhava

  • 0 in reply to Mihira Madhava Bollapragada
    TI__Prodigy 550 points

    Madhava, Thank you for your reply.

    > If you are looking to route the EXTSYNCIN to EXTSYNCOUT, please select any EPWM to sync with the EXTSYNCIN (via Inputxbar) ... 

    I think this is talking about the following paths highlighted with yellow. If so, yes, It is clear.

    > ... and then the set it for syncout on an event from the EPWM.

    This is what I am asking. Would you please elaborate a bit more? The reason why I could not understand this is because, I assume "ePWM and eCAP Sync Scheme" box highlighted with Magenta above should be the following figure.

    However, I can not find EXTSYNCIN in the above figure....

    Regards,

  • 0 in reply to mokkun
    TI__Intellectual 2297 points

    Hi Mokkun,

    I understand now. the Mux in Fig. 20-7 where the EPWMSYNCINSEL is shown, selects amongst the EPWMxSyncOut, ECAPySyncOut and Other Sources. this other sources includes the input-xbar-out 5 and 6 as well. 

    Here is a syscfg configuration to select them,  and the corresponding code generation in the board.c file. you can alternatively use the API EPWM_setSyncInPulseSource() to select the Sync In Source. Alternatively, Table 20-3. ePWM SYNC Selection from TRM lists these sources.

    Hope this clears your request. 

    Thanks and regards,

    Madhava