[Cryptech Tech] Alpha board BOM and PCB design requirements

[Павел Шатов]

On 09.03.2015 18:41, Fredrik Thulin wrote:
> Joachim and I had a (long) talk and produced the following initial suggestion
> for Alpha board components and PCB design requirements.
>
>    https://trac.cryptech.is/wiki/AlphaBoardComponents
>
> We tried to go the full circle from the block diagram
> (https://trac.cryptech.is/wiki/Hardware) and do some thinking about how each
> module could be implemented, but we might very well have missed things.
>
> Please read it through and comment on this mailing list.
>
> Copy the text you want to comment on as a quotation to the list and send
> comments in e-mail so that everyone can be a part of the discussion and so
> that we have all comments archived in the mailing list archive. Thanks.
>
> /Fredrik

Hello!

My thoughts are below.

> FPGA Configuration and Configuration Memory
>
>     The ARM CPU should be able to write configuration to the FPGA config memory. Write enabled should be controllable with a jumper.
>
> An alternative would be to make it like the Novena, that the ARM CPU can download config to the FPGA using I2C (this solution should also require a jumper present in order to be enabled)

1. I can't understand what configuration mode you want to use: Master or 
Slave? Where will the bitstream be stored? Btw, there's a typo, 
configuration can only be done using SPI, not I2C.

> External RAM
>
>     SO-DIMM DD3 modules. (Like the Novena.)

2. Do you intentionally want to have SO-DIMM connector instead of 
discrete chips?

3. I believe your sketch is missing 4th section named "Power subsystem". 
How is Alpha Board going to be powered?

--
With best regards,
Pavel Shatov