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How to stop a circular DMA at end of buffer

Question asked by VDM on May 24, 2017
Latest reply on May 25, 2017 by VDM

Hi,

 

I'm using an STM32F446.

 

I use the circular DMA feature with a DAC output to generate a sinus waveform.

My sinus buffer has 32 values.

 

What I would like to do is :

- run the DMA for a "large" amount of time

- be able to stop the DMA when I want, but only at end of buffer (so that the latest data sent to the DAC output is known and fixed).

 

I tried to change the "circular mode" to "normal mode" while the DMA is running (supposing the DMA would continue until end of buffer), but it doesn't work.

 

I know one of the way is to run in "normal mode" and use the "HALF-DMA" interrupt, but I would like to avoid this because it increases CPU load due to the interrupt.

 

Any idea ?

Thanks for help.

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