Fuzzy in PWM waves

Dear all,

First of all, Let me thank this discussion group for being active and
accepted me as a member. I am new to DSP . Having following doubts in PWM
generation.

*1)* If I generate PWM for the same frequency and duty ratio using Event
Manager A and Event Manager B and observe the PWMS in scope, I saw that
the PWMs using EV B is phase shifted by 284ns from PWMs using EV A. why
there is a differene of 284ns when I use the same frequency and duty ratio
for EV A as well as EV B? I kept zero dead band. I didn't get any error
during compilation and building my program. Something fuzzy.

Can any of you provide answer to me? Have you faced this kind in your
experience?

*2) *To generate PWM with specific delay, how do I know having
particular number in for loop provide this much delay? For example if I use
for (i=0; i%; i++) {},

How much delay will be introduced by this loop if I execute it in Event
manager subroutines?

I am eagerly waiting to know the answer for the above two queries from any
of you(experts).

Thank you all

Regards

Bala Start a New Thread

Dear all,
>
>First of all, Let me thank this discussion group for being active and
>accepted me as a member. I am new to DSP . Having following doubts in PWM
>generation.
>
>*1)* If I generate PWM for the same frequency and duty ratio using Event
>Manager A and Event Manager B and observe the PWMS in scope, I saw that
>the PWMs using EV B is phase shifted by 284ns from PWMs using EV A. why
>there is a differene of 284ns when I use the same frequency and duty ratio
>for EV A as well as EV B? I kept zero dead band. I didn't get any error
>during compilation and building my program. Something fuzzy���.
>
>Can any of you provide answer to me? Have you faced this kind in your
>experience?
>

this is normal, coz the two timers didn't start simultaneously. 284ns is the delay due to instruction execution.

u may search for "how to synchronize timers" from old posts.
>*2) *To generate PWM with specific delay, how do I know having
>particular number in for loop provide this much delay? For example if I use
>for (i=0; i%; i++) {},
>
>How much delay will be introduced by this loop if I execute it in Event
>manager subroutines?
>
>I am eagerly waiting to know the answer for the above two queries from any
>of you(experts).
>
>Thank you all
>
>Regards
>
>Bala
>


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