On 2006-03-15, Chris Liechti <cliec...@gmx.net> wrote:
> Grant Edwards schrieb:
>> I've been looking at the code generated by avr-gcc 3.4.5, and
>> it sure looks like there's a lot of extra overhead involved in
>> ISRs. Let's write an ISR that just toggles a port pin every
>> time the interrupt happens.
>
> you're posting that to the mspgcc mailinglist, don't expect too deep
> insight in the AVR architecture from us ;-)
Doh! That was obviously meant for the avrgcc mailing list.
I just hope you guys know how good you got it not having to
fight with the AVR's brokeness. I'm doing parallel
implimentations of some prototype code on MSP430 and AVR.
Everything is so much cleaner on the MSP430 except for the
MSP430's lack of a TX holding register empty flag and lack of a
TX shift register empty interrupt. At least Atmel got that
right in the AVR ATmega parts.
The code generated by gcc for small functions on the MSP430 is
a _fraction_ (like 1/4-1/5) of the size on the AVR. After the
functions get large enough that the prologue/epilogue don't
matter, AVR code is about 50% larger than MSP430 code.
And AVR parts are _expensive_. I honestly don't see why
they're popular at all...
--
Grant Edwards grante Yow! I smell a RANCID
at CORN DOG!
visi.com
