[avr-gcc-list] Problem with TWI and ATmega128

[Geoffrey Wossum]

Hi all,

I'm having problems compiling code to use the hardware TWI unit on the
ATmega128.  I'm using gcc 3.0.2 and binutils-2.11.2 patched for the
ATmega128, along with avr-libc-20020115.

If I try to compile the following piece of code:

---begin---
#include <io.h>
#include <twi.h>

void i2c_start(void)
{
    outp(BV(TWINT) | BV(TWSTA) | BV(TWEN), TWCR);
}
---end---

using 'avr-gcc -mmcu=atmega128 -O2 -c test.c', I get the following errors:

---begin---
test.c: In function `i2c_start':
test.c:6: warning: asm operand 0 probably doesn't match constraints
test.c:6: warning: asm operand 1 probably doesn't match constraints
test.c:6: inconsistent operand constraints in an `asm'
---end---

Why isn't this working?  Some simple blink some LED's code works, so the
tool chain is at least seemingly functional.

TIA,

---
Geoffrey Wossum
Project AKO - http://ako.sf.net

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