Using GPTx interrupt event for Input Capture Select of Edge-Timer (CC2650)

Michael Bittner

Hi all,

I'm trying to measure an external frequency.

I did set up GPT2A in edge-cound mode, which counts the falling edges (works) and GPT1A in edge-time mode. I would like to use the match event of GPT2A to trigger the edge-timer. Therefore I can get the needed time for e.g. 1000 falling edges and convert it into a frequency.

Is there a way to use the match event of a GPT?

I was able to use the compare event of a GPT, but I only got this event on time-outs of periodic timers...

I also tried to write the Event Number of the GPT2A interrrupt event (Technical Reference Manual - Table 4-6) into the Capture-Select Register but it didn't work.

HWREG(EVENT_BASE + EVENT_O_GPT1ACAPTSEL) = 0xC;

Any help or example code would be helpful.

Best wishes
MichaZ

over 10 years ago

0 Christin Lee over 10 years ago

TI__Guru 57895 points

Hi,

Please take a look at this thread. I believe it suits your need.

e2e.ti.com/.../507443

0 Michael Bittner over 10 years ago in reply to Christin Lee

Prodigy 90 points

Hi Christin,

thank you for your answer.
But unfortunately the link did not help... The driver in your link only uses an external event on a pin, which I was already able to use.
I want to use the Match Event of a counting timer as an Input Event of a timer in Edge-time Mode.

Micha

0 Christin Lee over 10 years ago in reply to Michael Bittner

TI__Guru 57895 points

If you don't want to use DMA to fire the 2nd timer. Then you can start another timer by Match event callback function, which might not be that exact.

0 Michael Bittner over 10 years ago in reply to Christin Lee

Prodigy 90 points

Hey Christin,

Thanks again for your answer.

I don't want to start the second timer on the match-event. I want to use the match-event of a counter as the input signal of the timer in edge-time mode:

I couldn't find a way to use a DMA-Event as the Input Signal. Could you please give me a code example, if there is a way?

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Using GPTx interrupt event for Input Capture Select of Edge-Timer (CC2650)