AVR-Chat

Thanks David,
You'd think there should be a way to tell, if it's mentioned in the documentation like that...
Regarding empty loops... we're not all as professional as you are :-)
Cat

> To: AVR-Chat@yahoogroups.com
> From: dkelly@hiwaay.net
> Date: Mon, 4 Jul 2011 17:05:09 -0500
> Subject: Re: [AVR-Chat] Delay functions and "__builtin_avr_delay_cycles".
> 
> 
> On Jul 4, 2011, at 2:55 PM, Cat C wrote:
> 
> > Hi there,
> > Looking at the delay functions, I see that:	void _delay_us 
> >          (
> >          double 
> >           __us )has a maximal possible delay is 768 us / F_CPU in MHz.
> > But:If the avr-gcc toolchain has __builtin_avr_delay_cycles(unsigned long) 
> > support, maximal possible delay is 4294967.295 us/ F_CPU in MHz.
> > How do I know if the avr-gcc toolchain has __builtin_avr_delay_cycles(unsigned long) support?
> > Thanks,
> > Cat
> 
> 
> "Use the source (sic) Luke".
> 
> Consult the avr-libc sources. I don't remember how much is shipped with WinAVR, or how much is shipped with AVR Studio 5.0. It doesn't really matter else I would go look because even if you go looking at the original source you need to build a test case and select "generate a disassembly listing" and have a look at exactly what code was generated. Else the original library sources you are looking at may not be the ones used for your CPU.
> 
> Burning CPU cycles in empty loops is usually a very amateurish and inaccurate means to an end.
> 
> --
> David Kelly N4HHE, dkelly@HiWAAY.net
> ========================================================================
> Whom computers would destroy, they must first drive mad.
> 

 		 	   		  

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