mohammad khademi

excution time

Discussion created by mohammad khademi on May 12, 2008
Latest reply on May 12, 2008 by Mark Butcher


hi
I writed this code on MCF5485:
//interuupt disabled
while(1)
{
        MCF_GPIO_PODR_FBCS=0x00;
        asm( nop);
        MCF_GPIO_PODR_FBCS=0xFF;
}


and then I connected one of MCF_GPIO_PODR_FBCS pin to the Osil. I measured the period of  signal.It was
about 4 microsecond.
I think it is wrong because my microprocessor is working on 200MHz.
the execution time of "NOP" instruction in my program is about 200 nano second when this instruction exution time is 6 clock cycle.(about 30 nanosecond)
I think it is unormal.
what is your idea?

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