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Re: [avr-libc-dev] Re: [bug #17216] change to the ../util/delay.h header
From: |
Joerg Wunsch |
Subject: |
Re: [avr-libc-dev] Re: [bug #17216] change to the ../util/delay.h header for increased functionality |
Date: |
Sun, 6 Mar 2011 22:02:12 +0100 |
User-agent: |
Mutt/1.5.20 (2009-06-14) |
As Weddington, Eric wrote:
> I question the whole viability of a _delay_ns() function. If someone
> wants a resolution that small, then they should be able to do the
> calculation and use the __builtin_avr_delay_cycles() builtin
> function instead.
But that way, you might as well question the other _delay_*s
functions. ;-) They have been created to take off the actual
cycle count calculation from the user, to the computer, that's
their only purpose.
Yes, it's only a few cycles, but the same is true for e.g.
_delay_us(12) on a standard AVR running at its default clock of 1 MHz.
I don't see a difference here to writing _delay_ns(300) on a modern
mega or xmega device running at 20 MHz, and be it only the
auto-documentation effect.
--
cheers, J"org .-.-. --... ...-- -.. . DL8DTL
http://www.sax.de/~joerg/ NIC: JW11-RIPE
Never trust an operating system you don't have sources for. ;-)