while statement

[karlo]

Hello,

I'm a beginner in programming PIC controllers in C, it's a little different the assembly language.

I made a loop with while statement
[code]
int8 count ;

while (count < 3 && PIR1,0 !=1) // no timer1 interrupt detected
{

count++ ;
}
//here the rest of the program//
When i simulate this loop, i'm stuck in this loop even when the condition is false count > 3 it still counts.
I've noticed that the green pointer of MPLAB SIM (when i the loop) never go next to the while statement and propably never check the condition.

Is this normal?
Shouldn't the condition been checked every loop within the statement?

Thanks

[D-Kens]

Try giving count an initial value at declaration, first ?
Then maybe put both of your conditions between brackets ?

[Ttelmah]

The second part of the line doesn't make any sense...
You can't use
PIR1,0
To access bit 0 of the PIR register. You either have to use a #bit statement to declare this, or use the 'bit_test' function.
The compiler does not complain about this, but produces no code for the invalid part of the statement. I'd presume this 'null code', is destroying the logic of the statement...

Best Wishes

[SET]

[Ttelmah]

Yes.
The compiler is throwing away the second part of the line, since '0!=1', simply evaluates as true all the time. Hence it optimises it away, and makes the loop permanent.
Not what is meant at all.
Good 'spot'...

Best Wishes

[karlo]

Hello,

You guy's are right.

The bit_test on the PIR1,0 !=1 ensures that the condition is checked and will stop the while loop if the conditiond are met.
This is what i did: