On 2/22/06, Lyle Johnson <kk7p@wavecable.com> wrote:
> > Question:
> >
> > If the DSP board proposed by Lyle were to be used is it
> > envisioned that it would be sitting on the LVDS buss? If so would
> > it be listen only or would it drive the buss at times ??
>
> Depends entirely on what the I/O requirements are for the other boards.
> The DSP board needs to communicate with the audio I/O and "IF I/O"
> boards, but only at DSP sampling rates of 200kHz or so. These are
> typically serial interfaces like I2S, so the data rate is on the order
> of 9 MHz or less. It will also likely need to configure/update various
> peripheral boards (command the DDS/Synthesizer(s), set gains, etc) but
> this is likely to be done using I2C or SPI style interfaces.
>
> Hopefully, LVDS won't be required for any of this.
>
> 73,
>
> Lyle KK7P
I would be just as happy if we forgot about LVDS on the backplane. If
we need to deal with a high freq. clock (> 20 MHz ???) we can LVDS it
to a two pin header (or something) and use twisted pair to run it to
its destination...
Can we get by with a two layer backplane - ground plane on top,
signal/power on bottom?
The LTC2208 Mercury board's initial mode will be to output serial I2S
data at <= 250 kSPS to the FPGA/USB or DSP board, so I don't need bus
speeds much over 10 MHz either.
73 de Phil C
_______________________________________________
Xylo-SDR mailing list
To post msg: Xylo-SDR@ae5k.us
Subscription help: http://lists.ae5k.us/listinfo.cgi/xylo-sdr-ae5k.us
Xylo-SDR web page: http://xylo-sdr.ae5k.us
Forum pages: http://www.hamsdr.com/hamsdrforum/
Archives: http://lists.ae5k.us/pipermail/xylo-sdr-ae5k.us/
Cecil Bayona
KD5NWA
www.qrpradio.com
I fail to see why doing the same thing over and over and getting the
same results every time is insanity: I've almost proved it isn't; only a
few more tests now and I'm sure results will differ this time ...