Low Cost Hardware Flaoting Point processor? whats available

I am sure you asked google, and found this already

I had a look at this, but I have noticed that they supply no timing specs, which leaves me a bit hesitant. I have emailed them, so I will se what they send back before I pass judgement.

The other problem i see it that they look like quite a small operations, which worries me a little. Considering I will only be needing around 150-200 units, this may or may not present a problem

Its looking like I may need double precision, so the suggested device is out of the question. Its looking more and more like a DSP solution is needed.

How about one of the 18 series PICs running at max. clock (40MHz?) and doing it in software? Don't Microchip also do a pseudo DSP PIC?

Mike Harding

Well, then I guess you have already consulted google and found a comparision between the micromegacorp unit and some other units, and there will be the info , so I wont bother.

I presume you have time invested in the Rabbit code. How about a small DSPIC as a floating point accelerator. Not sure how large the FP lib is, but an SPI-based accelerator isn't out of the question, without messing with your Rabbit too much.

There are a few DSPICs in low vol production-friendly packages.

Then you're poised for a complete redesign to DSPIC next time.... :-)

-Andrew M

investigating

on

If you are happy with a bit banged serial/8bit parallel interface then I presume that throughput isn't a primary factor? Are you offloading single calculations, or performing a bunch of calcs at once and then returning a result? For former is best done in the Rabbit in real time otherwise the overhead will likely be too much. The later is best served by a second processor or DSP rather than a dedicated FPU chip I would suspect. I guess that's why there ain't too many dedicated FPU chips these days.

How about a second Rabbit processor, it ain't no slouch in the FP department. Rabbit's aren't cheap modules though I suppose. Or else a DSPIC as someone else mentioned. I haven't used the Rabbit for a few years now, but I vaguely remember about dual procesor capability where you could tie the two together?

I remember many (4-5) years ago there being a pre-programmed PIC chip which was a dedicated serial interfaced FPU, but I can't remeber the name or find the link...

Dave :)

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Found it:

Don't think it's the exact one I remember, but is the same thing.

Dave :)

Doh. Already listed and discussed. Guess that'll teach me to read the whole thread!

Dave :)