[hpsdr] Sasquatch II

[Lyle Johnson]

>>> The way I read things, the development path for Sasquatch may be:
>>>
>>> 1) Port dttsp to the Beagleboard.
>>>
>>> 2) Interface the Beagleboard to ATLAS via OZY (USB).
>>>
>>> 3) Create a small carrier board (Son of Sasquatch) for the Beagleboard to
>>> allow its GPIO to interface to ATLAS.  This is very dependent on there being
>>> sufficient bandwidth, etc., for the FPGAs downstream to be loaded and
>>> interfaced (Penelope, Mercury, Phoenix/Janus).
>>>
>>> 4) Evaluate creating an OMAPL137-based board with the bus bandwidth for
>>> ATLAS, etc.  If this looks like a reasonable thing to do then...
>>>
>>> 5) Port dttsp to the OMAPL137.
>>>
>>> 6) Create the hardware OMAPL137 board (Sasquatch II).
>>>
>> Looks like the only reasonable custom board route to go down might be
>> the -L137 with the BGA256 package.   The cost of doing a board like
>> the Beagle Board with the OMAP3530 is going to be very very expensive
>> unless you do 1000+, I think.  The cost of prototypes might be just
>> horrible.  There was a discussion on the Beagle Board forum about
>> doing custom OMAP3530 boards and the quotes they were getting were
>> hair raising.  Looks like the Beagle Board is 6 layers, .4mm, with
>> blind vias, etc... not cheap stuff!
> 
> Lyle, any thoughts on this?

I looked at the design files for the TI OMAPL137 evaluation board. It 
has ten (10) copper layers.  I think this level of complexity is a 
non-starter.

Sasquatch was originally going to be based on the TMS320C6726 DSP, which 
is in a TQFP package.  The new DSPs include the TMS320C6745 which is in 
a 176 pin TQFP and should be able to be accommodated on a 4- or 6-layer 
PC board.  This is the same DSP as contained in the OMAPL137.

An approach like this would also separate the UI and its processor from 
the DSP and its tasks, doing in the physical hardware what is being done 
logically in software (SDRMAX for the QS1R, the next generation version 
of PowerSDR, etc.)

73,

Lyle KK7P

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