ARM controller with integrated DAC

Aug 16, 2010 30 Replies

Hi Nial,

we don't know much about FPGAs around here but get along with MVUs rather well.

During one test the same burst (consisting of ~50 values) is repeated over and over every 100 µs as often as desired, the actual number shouldn't matter.

Thanks for your feedback M'

If you need a really fast DAC, simply interface one to an XMOS chip:

formatting link

Development will be much easier than if you used an FPGA. You could buy one of these Sparkfun boards and XTAG2 for $100 and add a DAC to it:

formatting link

Hi Leon,

we didn't consider an FPGA. Our intention was to use an ARM (or a similar processor). Reason 1: familiarity Reason 2: price tag $1 - $2 While we could waive reason 1 it would only make sense if it offers a significant advantage for reason 2: arrive at a price tag below $2 at

1k units. I would be surprised if there are any chips (FPGAs or XMOS or ???) which meet this requirement, but then this domain is a foreign one for me.

Anybody knows if there are chips in this price range? Our requirements wrt gate count are probably rather low, given what is possible in modern hardware. (I know that 'rather low' is vague, but as I said we originally didn't consider it and it is foreign territory.)

Thanks for your feedback M'

The cheapest XMOS chip is $4.92 for 5000+. You might not be able to find anything that will do what you want for the price you quoted.

hip:

You can get a small CPLD (need milk^H^H^Hemory) for $1, couple with an external sram (free). You can pull sram chip out of any old motherboard (or module). Add an op-amp for 50 cents and you can build the whole thing below $2.

The OPs goals are not possible.

As a professed software guy, he does not understand the hardware requirements to do the task.

Or he has wishful thinking as most software people do.

My $.02

hamilton

Part only for CPLD is reasonable, FPGA is not.

Well, looks like there is no reason to not use an ARM. Thanks M'

Hi, looks like an ARM is a good fit then. Thanks M'

with a small ARM things look quite promising. M'

Yes, if you can live with whatever speed results. ie if DMA works ok for Size/Data rate.

5 Bits is ok from processor ports, tho you could add a Logic buffer device, if you want less Vcc noise.

A second step would be a 2nd chip, for the DAC-handling.

That could be either a separate processor, or you could use a small CPLD, to push your 5bit port rate to a 16bit port Mux'd 3 ways, and treble your workable DAC speed.

-jg

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required