RE: [avr-gcc-list] Using in/out Instructions with ATmega128

[Weddington, Eric]

> -----Original Message-----
> From: 
> address@hidden 
> [mailto:address@hidden
> org] On Behalf Of Thomas D. Dean
> Sent: Monday, May 04, 2009 4:37 PM
> To: address@hidden
> Subject: [avr-gcc-list] Using in/out Instructions with ATmega128
> 
> I have
> # avr-gcc --version
> avr-gcc (GCC) 4.3.2
> Copyright (C) 2008 Free Software Foundation, Inc.
> ...
> 
> I want to use the ATmega128 and in/out instructions for 
> registers below
> 0x40.  
> 
> # avr-gcc   -mmcu=atmega128  -c -o 4x40-lcd.o xxx.c

Also, you need to turn optimization on to get those IN/OUT instructions. Add 
-Os to your compiler flags.