Hi
What are the differences between ISR and a subroutine in embedded systems, how about the following:
- interrupts are disabled by the microprocessor prior to calling the isr
- isr's are always smaller
- an isr cannot be written in C
- a subroutine always has arguments
- the CPU flags are stored on the stack in addition to the return address
Thanks
Not always true.
not true
definitely just wrong
nope
Depends on the CPU
No problem
Sounds like a homework question, you want somebody else to answer for you.
Hint see if you can find a difference between interupts and functions on NON embedded systems.
Well I suggest you go back and read the book again, as these appear to be badly copied from a text book.
Stick it up your ass, cheat.
pete
It's the same in embedded systems as in every other system: an ISR is called by the processor after it has received a hardware signal, whereas a subroutine is called by software.
--=20 Fredrik =D6stman
This sounds like homework ?....
The key difference is that an isr must always store the processor status on entry, then restore it on exit. A subrouting function call doesn't necessarily need to. Both save the current program counter on entry and restore on exit
To get an idea why, look at something like the 68000 programmers reference manual - it's in pdf on the Freescale website. Chapter 5, exception processing...
Chris
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