[Oberon] New FPGA Oberon board

[skulski at pas.rochester.edu]

Joerg:
> If I got it right the ARM processor on the BBB is the host
> for the SD card and all the other peripherals.
> Can a cape access the interfaces on the BBB or do we need additional SD,
> HDMI, VGA, RAM capes to do that?

I think you misunderstood my point. I am not suggesting to build a cape
for the BBB. I am suggesting to build an FPGA board WITHOUT the ARM chip.
This board needs to be of the same dimensions (without rounded corners,
which we just the designer's fancy). The same pins, the same connectors
mounted in the same places. HOWEVER, all this will be driven by a single
FPGA.

In other words, I am suggesting to build a complete standalone single
board computer, much like Pipistrello, but all on a single board that will
have the same mechanical dimensions as BBB.

All the GPIO pins will go to the FPGA, regardless how they are named in
the BBB specs. The FPGA will be able to emulate the BBB pin functions
(such as I2C, SPI, etc) because any FPGA pin can do anything.

In this way we can get access to the BBB ecosystem: boxes, capes, and
application examples. But the actual board will be running the FPGA Oberon
System rather than Linux.

Is it more clear now what I am proposing?

Walter:

> I agree to adopt a standard. The FPGA world have some common pinouts also;
> FPGA Mezzanine Card (FMC) and Digilent PMOD.

You are talking of two opposite solutions in one sentence. FMC is an
expensive and tricky connector for multigigabit applications. It is
justified if you are going to use Multigigabit Transceivers (MGTs). The
present FPGA Oberon System is not going to benefit from these.

Digilent PMOD is an extremely cheap and simple connector system. It is the
exact opposite to FMC. This is the kind of connectors you want to
experiment with using the FPGA Oberon System. The PMODs can be easily
added on a cape.

> What would be the price that the community would accept pay for an Oberon
> FPGA board ? As small community this a very important question.

We recently got a quote for building a board very similar to BBB. (Same
hole sizes, same copper spacing, same number of layers, similar size). The
quote was $200 per board, if we order one hundred. It means, $200 per
board to build the boards. These boards would need to sell for $500 to
return the engineering cost. (I hope it clear what I mean?)

This community is realistically going to buy twenty such boards. Maybe
fifty. We are talking of a really small volume here. Correct me if I am
wrong. If someone knows how to get around it, then please make the
suggestion.

The essence of my proposal was to address people outside this community by
making the board compatible with a widely adopted standard. This can
perhaps increase the volume.

Chris:

> As for price anything under $US150 for a new system would be less than is
> currently available for an Oberon FPGA system. Under $US100 would be a
> bonus.

BBB is sold for $55 because they found a way of selling a quarter million.
If you are dreaming of a cheap board manufactured in low volume then I am
afraid it is not realistic.

I would like to hear from Magnus how he can possibly achieve such a goal.
Magnus, could you please e-mail me and tell me which assembly house are
you using? I will give them a call right away.

Thank you,
Wojtek