Re: Computational power AVR vs. MSP430?

From: David Brown (david_at_no.westcontrol.spam.com)
Date: 12/29/03 

Date: Mon, 29 Dec 2003 09:41:50 +0100

"John R. Strohm" <strohm@airmail.net> wrote in message
news:bsbpfs$j90@library2.airnews.net...
> "Dr. O" <dr.o@xxxxx> wrote in message
> news:3fe952f1$0$64979$1b62eedf@news.euronet.nl...
> > Does anyone have any idea how AVR and MSP430 compare in terms of
floating
> > point and integer math? We need to do some computational number
crunching
> > (preprocessing) in our devices but aren't sure which of the above to
pick.
> >
> > The MSP430 is 16 bits so it should be faster in math it seems to me, but
are
> > there other aspects which are important? The computations are 'DSP like'
> > (lots of adding amd multiplication).
>
> The first thing you have to quantify is HOW MUCH adding and multiplication
you
> have to do.
>
> How wide are the operands? How many per second do you have to process?
>
> If you are doing multiply-and-accumulate kinds of things at DSP rates, you
> probably need a real DSP.
>
> My understanding is that neither AVR nor MSP430 have hardware floating
point,
> which means that floating point operations will be *S*L*O*W*.
>

The original AVRs do not have hardware multipliers, but the Mega ones do.
The mps430f13x family does not have hardware multipliers, but the msp430f14x
family does.

If you are looking to do heavy maths with these chips, however, it is
important to know exactly what you are looking for and try to find
short-cuts. For example, if you are only going to be working with a number
of fixed constants, you could be faster with look-up tables (the mega128 has
a fair amount of flash space for tables). For floating point, think about
the accuracy you need.

In general, however, the msp430 is likely to have the edge by being 16-bit,
even though the avr has a faster clock and instruction-per-clock rate.

Relevant Pages

  • Re: Computational power AVR vs. MSP430?
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