Interval timer problem

I measure strobe with oscilloscope.

I describe behavior of my code

In main function (int foo(void)) I set strob signal in high level by

IOWR_ALTERA_AVALON_PIO_DATA(PIO_BASE, 0);    //set PIO

(cause I has inverter on ouput pin).

Then init timer to 10ms, and start it.

Enter endless loop and wait for interrupt. I expect it takes 10ms to get interrupt. But it takes much longer because init functions work so slow in uC.

In interrupt handler I deactivate srobe and timer.

IOWR_ALTERA_AVALON_PIO_DATA(PIO_BASE, 1);

timer_exit();

That’s all.

Time to exec

timer_exit(); 
err=1;

and following instructions doesn’t meters because I measure time between

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IOWR_ALTERA_AVALON_PIO_DATA(PIO_BASE, 0);

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and

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IOWR_ALTERA_AVALON_PIO_DATA(PIO_BASE, 1);

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