RE: [avr-gcc-list] port access with avr-gdb

[Larry Barello]

We are talking I/O and registers: just how portable can those be???

Or are you talking about porting code between compiler vendors for the same
chip?  Do makers of  C compilers randomly choose between low to high and
high to low for bit field assignments? Or does it more have to do with the
architecture: big vs little endien and/or any data space access requirements
peculiar to that hardware?

-----Original Message-----
From: Joerg Wunsch

"David Brown" <address@hidden> wrote:

> What sort of portability are you looking for?  Being able to take a
> program for an AVR and run it unaltered on an MSP430?  Being able to
> take a program for gcc-avr and being able to compile it unaltered on
> iar-avr?

The way the macros are currently arranged matches the way Atmel uses
in their datasheets (which has most certainly been influenced by the
way IAR does it).  There are still enough further compatibility issues
between IAR and GCC, sure (notably GCC's missing ability to handle
memory sections automagically), but the direct assignment of IO
registers helps quite a bit (together with using the exact register
names as described in Atmel's datasheets).