Re: [avr-gcc-list] Setting pin to high in function instead of main, instructions in main never run?

[Bernard Fouché]

Le 01/03/2012 11:25, Richard Zetterberg a écrit :
> I have a ATmega328-PU chip which I have programmed with a bare minimum
> program which sets PB0 to output and then runs a function which sets the
> pin to HIGH. The problem is that the voltage output of the pin is at
> 10-20% of what it should be, identical to what it would be if the pin
> was set as input and the pull upp would be active. However if I set the
> function as static, it works as expected. I have tried this on 3
> ATMega328-PU's with default fuse settings to minimize the things that
> could contribute to the problem.
The only difference that appears in the different examples is the 
function call for the non-static version: is the stack pointer correctly 
initialized? If what you show is a complete disassembly then it misses 
r1 init, stack pointer init, etc. Code should also be generated for 
addresses higher than 0x0 since the interrupt vectors are starting at 
this place. Seems like avr-libc isn't considered at link time.