Thread: Software Defined Radio DSP choice / sizing
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Old June 22nd 07, 03:58 PM posted to rec.radio.amateur.homebrew,comp.dsp
Vladimir Vassilevsky Vladimir Vassilevsky is offline
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First recorded activity by RadioBanter: Jun 2007
Posts: 3
Default Software Defined Radio DSP choice / sizing


wrote:

I'm working on a SDR design using the AD9874 to

Fair performance is guaranteed.

digitize the IF producing 280 Ksamples/sec and
am trying to size the DSP.

Get the biggest one. Like Intel P4.

I'm leaning towards
the ADSP-BF532 which is a fixed point DSP rated
at 400 MIPS / 800 MMACS

800 MMACS is a pure marketing. The 400 MIPS is closer to the reality.

and is available in a LQFP
package. I'd like to be able to handle everything
from decoding standard shortwave SSB signals to
broadcast FM stereo signals (including RDS).

I like your optimism.

1) Any pointers to information which can be used
to size the DSP in terms of MIPS, program RAM,
and data RAM? Something like a minimum of X MIPS
are needed to do a reasonable job handling
broadcast FM stereo signals (which I'm assuming
require more MIPS than SSB) would be useful
to know.

* It depends
* The barebone DSP functionality will take about 20...30 kbytes of the
program memory and several kbytes of the data memory.
* For the single channel processing, the workload should not exceed
about 100 MIPS.

2) Anyone have a specific DSP they favored for
this type of application?

It doesn't matter. Whatever DSP you wil take, you will be screwed many
times.

Keep in mind I
need the DSP to be in a package I can handle
using home equipment.

)))))

It would be nice if the
DSP was flexible enough so that it can be used
for general purpose things such as controlling
the keyboard and LCD instead of adding a
microcontroller.

The general purpose stuff can easily boost the program size over the DSP
internal memories.

I'm not looking to use a FPGA at this time.

Why don't you start learning DSP with something simple like FIR or IIR
filter?


Vladimir Vassilevsky

DSP and Mixed Signal Design Consultant

http://www.abvolt.com
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