i.MX RT1052 - Is it possible to connect PIT trigger output to the input of Quad timer?

[Cindy]

Hi,

i.MX RT1052 - Is it possible to connect PIT trigger output to the input of Quad timer?

This is so that PIT trigger output can be used to trigger the pulse generation from the quad timer.

Thank you!

Best Regards,

Cindy

[kerryzhou]

Hi @Cindy 

   Thank you for your interest in the NXP MIMXRT product, I would like to provide service for you.

   Why you need to use the PIT to trigger the QTMR? Do you want to use the PIT to periodly sendout the PWM?

   In fact you can use the QTMR output the PWM directly, if you really want to use the PIT trigger, you can use the PIT get the interrupt, then add the QTMR code in the PIT interrupt code to trigger the QTMR.

  Wish it helps you!

Best Regards,

Kerry

[Cindy]

Hi Kerry,

Thank you for the prompt reply. I just wish there is a PIT hardware trigger output to trigger the quad timer. Then, using the XBAR to connect that trigger output to the quad input to generate a single pulse of set width, say, 300ms.  In that case, there is no need to cascade 2 quad timers together to get a 32-bit timer.

Also, if we can do it in that way, we can control  the interval between the pulses using PIT trigger output. Using the interrupt might not be a way since software will have to keep servicing the interrupts.

We are tight in finding spare output pins. If we cascade 2 quad timers together, what is the best way of ensuring the period of the PWM output is changed only on the completion of last period? Or will the PWM module handle this change automatically? Let me know should you need more details of what we intend to do.

When cascading 2 quad timers, can we use any of the quad timers? Say, TMR1 Channel 0 cascaded to TMR 1 Channel 3, or, TMR1 Channel 1 to TMR2 Channel 0?

Your feedbacks are very much appreciated.

Thank you.

Best Regards,

Cindy

[kerryzhou]

Hi @Cindy 

Please check the following post:

https://community.nxp.com/t5/i-MX-RT/PWM-VARIABLE-DUTY-CYCLE/m-p/958047

The PWM duty can changes with the DMA, so I think you also can use the CPLD1 CPLD2 buffer to generate your sine duty wave. This is using the QTMR+DMA, you even don't need PIT, XBAR, etc.

If you still have question about it, please kindly let me know.

Best Regards,

Kerry