[dsp] Analog front end design

[doug at dougbraun.com]

The venerable Motorola 56002 EVM  has a great G3RUH modem, and
it does only 13 MIPS with a 27 MHz clock.

And I think 10 bits of ADC resolution is plenty.  Its SNR is probably
better than you ever get from an actual received FM signal.

So go for it...

Doug Braun
NA1DB
www.dougbraun.com


At 08:40 PM 4/25/2005 -0700, scott at opentrac.org wrote:
>I'm not actually using a dsPIC - at least, I have no plans to at the moment.
>I'm using an AT91SAM7S64, which has an ARM7TDMI core at around 50 MHz.  A
>multiply takes 4 cycles and it's got a load-store architecture, so it's not
>going to keep up with a 'real' DSP.   I *know* it can be made to do 1200
>baud AFSK well in 4 MIPS or less, but unfortunately I don't have access to
>the proprietary code that proves it!  Wouldn't mind licensing it if I could.
>
>I think it can be made to do 9600 baud, but I haven't really experimented
>with it yet.  There's no 9600 baud activity around here and it's going to
>take some effort to get a real-world test environment set up.  I also need
>to do more research on GMSK and G3RUH, and look into compatibility with
>existing hardware.