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About "CTR = zero pulse" of Piccolo ePWM

sugita
Intellectual 270 points


Hello Everyone,

 

I have questions about Time-Base Submodule of piccolo ePWM.

When is CTR = zero pulse generated? TBCTL[PHSEN] is set.

I understand that CTR = zero pulse is generated on below condition when TBCTL[PHSEN] is set.

(1) Count-up; 0xFFFD, 0xFFFE, 0xFFFF->0x0000

(2) Count-down; 0x0003, 0x0002, 0x0001->0x0000

 

My question is below.

(3) When EPWMxSYNCI or DCAEVT1.sync or DCBEVT1.sync is detected, 

phase register is loaded into the counter register.

If TBCTR is change form 0xABCD to TBCTR=0x0000, 

is CTR = zero generated? (In this case, TBPHS is 0x0000)

 

(4) When condithon is same as (3) and TBCTR encounter 0x0000,

TBCTR is not change (form 0x0000 to 0x0000).

In this case, is CTR = zero generated? I think answer is NO...

 

Thank you,

 

Nathan

  • 0
    Intellectual 270 points

    Hello,

     

    I ask simply. My question is as below.

    Is ePWM[n+2] synced by TB_CTR_CMPB and DC_COMP1OUT in PWM_PSFB_PCMC_Cnf.c ?

     

    I hope somebody tell me.

     

    Best regards,

     

    Nathan

  • 0 in reply to sugita
    TI__Genius 10820 points

    Nathan,

    Please let me know if the answer to your 2nd post (Re: C28x Digital Power Library) doesn't answer this question as well or if you need further clarifications.

    Thank you,

    Hrishi

  • 0 in reply to Hrishi Nene
    Intellectual 270 points

    Hello Hrishi,

     

    Thank you for your kind and  I'm sorry wrong question. 

    I want to know factor of CTR = Zero pulse. 

    Can you see Figure 10 of page 31 of spruge9e.pdf, please ?

    If the value in TBPHS is ZERO, is CTR = Zero signal generated by EPWMxSYNCI signal ?

     

    Best regards, 

     

    Nathan 

  • 0 in reply to sugita
    TI__Genius 10820 points

    Nathan,

    If TBPHS = 0, the CTR will start counting from 0 on a SYNCI event. If the PWM module is configured to generate a SYNCO on a CTR = 0 event, a SYNCO will be generated from this PWM module (at CTR = 0 i.e. when TBPHS gets loaded).

    However, if SYNCO out of this module is based on SYNCI coming in to this module, a CTR = 0 event in this PWM module will not have any effect on SYNCO. In this case the SYNCO is based on the SYNCI signal coming into the module from a PWM module that is up the chain or from an external SYNCI signal.

    Hrishi