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EXTI - High Latency on STM32F407

Question asked by s.i.001 on Jun 27, 2013
Latest reply on Jun 28, 2013 by s.i.001
Hi.

I used one of the examples shipped with Discovery as a template for my code.  Basically, a GPIO input (PA0) is coupled to a function generator and every time an interrupt is detected, a different pin goes HI/LO to indicate that whatever is inside the interrupt handler gets processed.

The problem is that the test GPIO goes high and low (indicating a registered interrupt) approximately 600 ns after the detection of the rising edge of the input signal.  Now, without some stuff in the main while loop (a serial port polling routine), the latency is reduced to about 440 ns.

Shouldn't the interrupt handler process the interrupt much faster than this?

Thank you,
Razvan

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