AURIX™ Forum Discussions

[NimsocCh]

Hello,

The application must start blue PWM signal on a defined point during first signal ramp and stop the same PWM on the second ramp also in a defined point.

The points are detected using Fast Compare module from EVADC. For each ramp a different FC channel is used.

Start point (PWM start) is running well using FCxBFL flag routed through TIM them to ATOM (trigger to reset CN0).

For asynchronous duty-cycle update I found:

"For an asynchronous update of the duty cycle and/or period the new values must be written directly into the
compare registers CM0 and/or CM1 while the counter CN0 continues counting."

Interrupt must avoid because introduce a delay on PWM stop command.

How can I stop PWM on the second point ? 

I tried Shut-Off feature from DTM but the dead-time is missing.

[Jeremy_Zhou]

Hi @NimsocCh ,
Thank you for your interest in Infineon Semiconductor products and for the opportunity to serve you.
According to the above statement, whether you want to use the same event of EVADC to trigger the ATOM start or output PWM or terminate output via the pure hardware mechanism, is my understanding right?
BR,
Jeremy

[NimsocCh]

Hi @Jeremy_Zhou 

If it is possible, otherwise I want to use Fast Compare channel 0 to start PWM and Fast Compare channel 1 to stop PWM for each PWM period.

[Jeremy_Zhou]

Hi @NimsocCh 
Thanks for your reply.
According to your statement, you had already routed a trigger from the TIM to the ATOM to start outputting PWM, I think you can also select a similar trigger source to stop outputting the PWM, just as the below shows.

BR,
Jeremy

[NimsocCh]

Hello @Jeremy_Zhou ,

This feature will stop PWM output (end duty-cycle period) until next PWM period? 

[Jeremy_Zhou]

Hi @NimsocCh 

After digging deeper, I think the shut-off feature is the better choice for your design, in my opinion, 'use Fast Compare channel 0 to start PWM and Fast Compare channel 1 to stop PWM for each PWM period' is able to make it.
I was wondering if you can clarify the "but the dead-time is missing", as I haven't no idea about it.

BR,

Jeremy

[NimsocCh]

Hello @Jeremy_Zhou 

When shut-off is triggered by fast compare channel the PWM outputs routed through DTM module will switch to defined output state without adding any dead-time in that moment (PWM end).

[Jeremy_Zhou]

Hi @NimsocCh ,

Can you illustrate the PWM you expect when the fast compare event happens?

BR,

Jeremy

[NimsocCh]

Hello @Jeremy_Zhou 

The PWM must behave like in image.

Thank you! 

[Jeremy_Zhou]

Hi @NimsocCh ,

After going through the GTM IP specification, I'm afraid that the GTM hasn't supported the feature, maybe you can try to contact the expert of BOSCH for some advice.

BR,

Jeremy