Lpc2000

> > typedef struct {
> >   reg32 MR0INT          :1;
> >   reg32 MR0RES          :1;
> >   reg32 MR0STOP         :1;
> >   reg32 MR1INT          :1;
> >   reg32 MR1RES          :1;
> >   reg32 MR1STOP         :1;
> >   reg32 MR2INT          :1;
> >   reg32 MR2RES          :1;
> >   reg32 MR2STOP         :1;
> >   reg32 MR3INT          :1;
> >   reg32 MR3RES          :1;
> >   reg32 MR3STOP         :1;
> >   reg32                 :20;
> > } __mcr_bits;

The problem here is that gcc for bit field access will generate 8/16/32 bits
access depending on the width of the bit field. This is allowed for memory
based operations if the memeory accepts 8/1/632 bit transfers (most
configurations do), but deadly in case of I/O registers that can only be
written 32 bits at a time.

We have seen large projects where the original sources with I/O as bitfields
(ADS or Greenhills compiler) were all rewritten into macro's for use with
the GCC toolchain.
We also stay safely with that method   ;-)

Regards,
Arie de Muynck