What is IVT & ISR in C?

[vkumar]

what is ivt and isr?

Actually i am new in c but i am desired to learn making TSR but i have a problem, i dont know about Interrup vector Table and Interrup Service Routine. But i have light knowledge about memory management. So please please please Provide me some material or tutorial notes and source code about this.

 

[mmike]

http://tigcc.ticalc.org/tut/tsrclock.html

 

[Soyuz]

IVT = Interrupt Vector Table

-- This is a table maintained by OS for the what function to call for interrupts. So you can think of it as in one column having the ID of an interrupt and the other column contains the function pointer that should be executed in case of that interrupt happens.

ISR = Interrupt Service Routine.

-- Any function that is executed against an interrupt is the ISR for that interrupt. ISR address is the second column in the IVT


Now you can see that, even though the OS will build a default table to make sure that every interrupt is served by a corresponding function, it is possible to overwrite the entry in the *IVT* with your own *ISR address* so that you can do your own stuff for that interruprt ...