Lpc2000

At 10:57 AM 5/12/05 +0200, 42Bastian Schick wrote:
>Kasper,
>
> > Inline asm, that I have found and plan to use:
> >
> > #define IENABLE                       \
> >   __asm { MSR     CPSR_c, #0x1F }    /* Enable IRQ (Sys Mode)   */   \
> >
> > #define IDISABLE                      \
> >   __asm { MSR     CPSR_c, #0x92 }     /* Disable IRQ (IRQ Mode)  */   \
>
>
>a) You must be sure you are in ARM mode.
>b) You must be at least in SYS mode.
>c) You should not switch CPU state unless you are sure you know what you
>are
>doing :-)

to which I would add

d) use a disable/restore pair rather than a disable/enable pair.

>I always suggest a small assmembly routine.

Also a simple commented version available in the newlib-lpc 
support.  Easily separable.  GNU based but short and simple.

Robert

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