TIMER Interrupt and Other Interrupt

[vbesson]

Hello All, 

I am progressing toward my goal. 

I am bit banging a GPIO port every 2 uS based on a Byte buffer. I can not use SPI because I need to send a predefine number of bit that is not 8 aligned. 

So I use a timer and every UIF event I reset the GPIO and every CC2F I set or not based on the bit.

Everything is almost working well except that using a logic analyser I have time to time delay in the bit banging. 

I think it is due to other interrupts, I have already disabled the DMA and the SDIO but still I have delay. 

I am using VSCode on Mac with CubeMX, how could I know which interrupt is causing delay 

 

Except disabling one by one, I do not see how to do it 

Thanks 

Vincent 

 

[TDK]

> how could I know which interrupt is causing delay 

Look at the interrupts you have enabled which are same or higher priority than the one you process UIF in. Probably SysTick is causing it.

[vbesson]

Well systick has a priority of 15 and my TIMER a priority of 0 

so It might be something else

 

[TDK]

A priority of 0, although numerically lower, is a higher priority than 15. That's it. Swap them.

[Andrew Neil]

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@vbesson wrote:

I can not use SPI because I need to send a predefine number of bit that is not 8 aligned. 

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You might still be able to use SPI - just set the excess bits to whatever the line idle state is ...