Re: [avr-libc-dev] Sleep.h not appropriate for AT94K devices

[E. Weddington]

Wouter van Gulik wrote:

> Well the e-mail address that is on almost every file, pdf, CD and eval kit
> is:
>
> address@hidden
>
> I suggest you try this one.
> Please note that the current cd I have (SystemDesigner 3.0) is dated 2003.
> I requested the latest version from my local resaler and I got this version.
> So they might be aware of newer version.
>
>  
Ok, thanks. I'll contact them and see what they say.

>  
>
> Well there is this one thing that really bothers me but it's more a compiler
> issue I guess.
>
> If I make a construction like this:
>
> PORTB = 1<< someUnsignedCharVariable;
>
> Then the compiler promotes the "1" to an int and therefore generates some
> extra code:
> Example:
>
> eor r25, r25
> ldi r24, 0x01
> add r24, r24
> adc r25, r25
>
> But finally it only uses r24, leaving r25 unused.
>
> out PORTB , r24.
>
> I tried various other options but I just don't seem to get the compiler to
> handle the 1 as a char.
> Shifting with a constant however works fine. (no promotion to an integer)
> Any suggestions?
>
>  
Known issue. This has to do with the C language itself. See the avr-libc 
user manual, FAQ #20:
<http://www.nongnu.org/avr-libc/user-manual/FAQ.html#faq_intpromote>

HTH
Eric