[Cryptech Tech] Alpha board main CPU change

[Jacob]

On 5/28/2015 11:48 PM, Fredrik Thulin wrote:
> Hi all
>
> We've just finished two days of core team face to face meetings in Stockholm.
> During these days, we unanimously decided to change the design for the
> upcoming Alpha from using an ARM A9 to an ARM M4.
>


> So... those interested might want to download the latest and greatest file
> from https://wiki.cryptech.is/browser/doc/design/Alpha_board_drawing.pdf
>
> (briefly, the plan is to use an STM32F4429 ARM Cortex M4 CPU running at 180
> MHz. 128 MB of SDRAM, using the FMC interface to connect to the FPGA instead
> of the Freescale EIM interface. As I understand it, the FMC interface will be
> at least as fast as we were going to push the EIM).
>

STM32F4429 -> STM32F429

The ARM M4 has RTC in it, so I guess the external RTC chip is now redundant.

Also, realizing that I don't have any of the credentials required to 
enter into the sanctum sanctorum of the crypto world, and I know that 
this is bordering on heresy, but since M4 has a TRNG, will you trust it? 
If yes, what benefit is provided by the noise board, if any?
If not, why would you trust the M4 to manage your external TRNG and FPGA 
core I/F?