A simple MC program !!

[Peter Nabil]

Hi every single one
I AM GOING CRAZY AGAIN
I wrote this program to check the pin p2.2 , and then output the corresponding action on pin p2.4,
But the problem is the micro controller is working in the real time, by another meaning, when I change the input status the output changes !!
And I am wondering is there no end for this program !!!
I think the microcontroller check the input then make an action, then END.
But in reality it continues looping
Org 0H
Jnb p2.2,Finish
Sjmp Finish
Clr p2.4
Finish:END

 

[Jay.slovak]

Hi every single one
I AM GOING CRAZY AGAIN
I wrote this program to check the pin p2.2 , and then output the corresponding action on pin p2.4,
But the problem is the micro controller is working in the real time, by another meaning, when I change the input status the output changes !!
And I am wondering is there no end for this program !!!
I think the microcontroller check the input then make an action, then END.
But in reality it continues looping
Org 0H
Jnb p2.2,Finish
Sjmp Finish
Clr p2.4
Finish:END

Ofcourse it will loop. What it does is that it will jump to the Finish label, and then it will run series of NOPs until it will reach the end of program memory and wrap around to the ORG 0 again.
To stop it, simply add Goto $ instruction.

 

[Nigel Goodwin]

Hi every single one
I AM GOING CRAZY AGAIN
I wrote this program to check the pin p2.2 , and then output the corresponding action on pin p2.4,
But the problem is the micro controller is working in the real time, by another meaning, when I change the input status the output changes !!
And I am wondering is there no end for this program !!!
I think the microcontroller check the input then make an action, then END.
But in reality it continues looping
Org 0H
Jnb p2.2,Finish
Sjmp Finish
Clr p2.4
Finish:END

A computer program does what you tell it to do, not what you would like it to do! - there's often a BIG difference.

I've no idea what processor you're using, but you're not stopping the program running at all - so presumably it will run completely through memory and loop back to the satrt and run again?.

If you want the program to 'end' you simply add an andless loop, for a PIC it could be something like this:

Finish: GOTO Finish

Which makes that line loop for ever.

 

[mstechca]

Hi every single one
I AM GOING CRAZY AGAIN
I wrote this program to check the pin p2.2 , and then output the corresponding action on pin p2.4,
But the problem is the micro controller is working in the real time, by another meaning, when I change the input status the output changes !!
And I am wondering is there no end for this program !!!
I think the microcontroller check the input then make an action, then END.
But in reality it continues looping
Org 0H
Jnb p2.2,Finish
Sjmp Finish
Clr p2.4
Finish:END

Since I deal with opcodes instead of text commands, I can't help you much with the arrangement of the code.

If I am right, What happens when the code runs is that you are starting at the beginning (org 0H), and because a bit is not set, you ask the program to go to the end. Once the end is reached, whatever is coded in the chip after the address of the "finish:end" instruction will execute.

What microcontroller do you use?

 

[Peter Nabil]

Thanks mstechca, Nigel Goodwin for your support,
Your idea works properly, but I really wonder what's the job of end command ?!!
Is it meaningless?!!!
Thanks a million

 

[Jay.slovak]

Thanks mstechca, Nigel Goodwin for your support,
Your idea works properly, but I really wonder what's the job of end command ?!!
Is it meaningless?!!!
Thanks a million

The END is a Directive, which tells Compiler where user commands end in the ASM file... That's all. MCU won't see it.

 

[Nigel Goodwin]

Is it meaningless?!!!

As Jay says, it's just an instruction to the assembler - so it knows to stop looking for any more lines.

 

[mstechca]

[quote="Peter Nabil"...but I really wonder what's the job of end command ?!!
Is it meaningless?!!!
Thanks a million[/quote]

To me personally, yes.

To 99.9% of the compilers, no. The END statement typically means thats the end of the code.

But if you are like me and want to force an END statement, simply create a jump statement that goes to itself. A.K.A. an endless loop. LOL

OR

better yet, create a special bit pattern and use logic gates to detect it, and once it is detected, prevent the on-board clock from running, and then the controller shuts down!