fx2 interrupt int0

Thank you for this information. I made it as you described.

In the main() where I initialize the Interrupt I added the line #pragma NOIV

In another file I put the ISR.

The USB tranfer is not disturbed now. Thats an improvement for the problem. But there's a further problem.

In the ISR I increment a variable. This variable I send over USB to my PC to see if the ISR ran. But it is not incremented. Incrementing it in a "normal" function is going well.

I declared the variable in ane xtra header file. The two files (file with main() and the file with the ISR) now see the varibale.

static volatile char value=0;

By the way, there is no compilation error. Can you see a failure?

Thank you for this information. I made it as you described.

In the main() where I initialize the Interrupt I added the line #pragma NOIV

In another file I put the ISR.

The USB tranfer is not disturbed now. Thats an improvement for the problem. But there's a further problem.

In the ISR I increment a variable. This variable I send over USB to my PC to see if the ISR ran. But it is not incremented. Incrementing it in a "normal" function is going well.

I declared the variable in ane xtra header file. The two files (file with main() and the file with the ISR) now see the varibale.

static volatile char value=0;

By the way, there is no compilation error. Can you see a failure?

static volatile char value=0;

Why did you make it 'static' ... ?

Think about what effect that might have...?

You might want to take a look at this thread on the subject of 'static':

http://www.keil.com/forum/16651/

When I make it static and I have included this file in both files I'll have a copy of this variable? The variable exists now two times in the stack?

But how can realize it having two files and both know this variable?

When I make it static and I have included this file in both files I'll have a copy of this variable? The variable exists now two times in the stack?
1) NO variables "exist on the stack"in C51
2) either you get an error or you have two SEPARATE variables, it is an issue of 'scope'

you need to read up on global variables and 'extern' (and header files??). Please do not respond with the usual BS about global variables.

the only way you can communicate between a function and an ISR is having them in the same module or using a global variable

Erik

And 'static' variables don't (generally?) exist on the stack anyhow!

"the only (sic) way you can communicate between a function and an ISR is having them in the same module..."

Strictly, in the same Translation Unit - in which case you'd need a variable at File Scope.

"...or using a global variable"

I guess you could also do something really horrible with absolute memory locations...

This is 'C' textbook stuff!

See: c-faq.com/.../decldef.html

the only way you can communicate between a function and an ISR is having them in the same module or using a global variable

Yes, but how can I realize it making it global when I use two files which have to access this variable?

could I make it as follows:
creating a new file
_______________________
globalVars.h:

static volatile char var;

static char getVar()
{ return var;
}

static incVar()
{ var++;
}

________________________

Whenn accessing the variable from the ISR or main file I call the getVar()
fucntion. Does this realization create two variables internaly too?

But was it too simple to remove the "static" keyword, thereby allowing access to the variable from other translation modules?

Then a line with "extern" to tell the compiler that someone else has a variable of this type and name that it wants to share with the world.

Surely, you must realise every 'C' program with more than 1 source file must manage to do this?
It really is basic, textbook stuff!

Did you actually follow the link that I provided?

Have you actually thought about the meaning of the 'static' keyword?

Problem solved. Thank you!