On Wed, 27 October 1999, Byron A Jeff wrote:

 Think of it in terms of your house electricity.
 You have the MAIN circuit breaker (Fuse) which
 enables all the lights in the house.  You now have
 to turn on each light if you want to use it.  You
 don't have to use the MAIN to turn the lights on and
 off.  Likewise, if you don't have the MAIN on, you
 can't use any of the lights in the house.  So to
 parallel your question in terms of the house
 electricity, would be to say "Why do I have to turn
 on the MAINS.  All I want to do is turn on the living
 room light.  I don't want to use them all."
 I hope this makes it clearer.

                                 Regards,

                                   Jim






>
> >
> > I realise that but what if I do not want to use all interupts. Why would I
> > want to enable them all???
>
> You've misinterpreted what she's saying. When the GIE is off, all interrupts
> are disabled. However when the GIE is on, then any interrupts that have been
> enabled by setting the individual interrupt enable flags are then turned on.
> Think of GIE as the interrupt mask in other architectures, where all interrupt
s
> are disabled when it is off but interrupts are allowed to happen if it is on.
> You still have to enable the individual interrupts also.
>
> BAJ

jim@jpes.com