How to return to a particular line after ISR is executed???

[saraheem]

I am using AT89s51 and programming with embedded C (Keil uVersion4 demo version).
I am writing a program that has a number of routines of which one is called sig_ctrl(). I am also using Interrupt 0 in my proj.

My question is this:

After the ISR is executed i want my program to ALWAYS continue executing from the start of sig_ctrl() routine only and should NOT return to where the program was being executed prior to the interrupt was sensed. If i use a jump (i.e. calling sig_ctrl() ) statement, then the uC will still be inside the ISR only, which i dont want to happen as this might cause trouble. How can this be done...? Pls give ur ideas...

Thank you...

 

[matbob]

Re: How to return to a particular line after ISR is executed

Hi saraheem,

"If i use a jump (i.e. calling sig_ctrl() ) statement, then the uC will still be inside the ISR only"

I don't think so because a jump is an unconditional branching and is different from calling a subroutine. So a simple jump instruction would be enough. Also clear interrupt flags if required.

If not, try doing this: When you reach the ISR, pop the stack and push to the stack the address to which you wish to move once the ISR finishes.