[Cryptech Tech] STM32 FMC problem

[Joachim Strömbergson]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256

Aloha!

Peter Stuge wrote:
> Pavel Shatov wrote:
>> First part of the problem with STM32 is that, if it tries to read
>> or write from an unprogrammed FPGA, it hangs.
> 
> Why would it do this? Doesn't the STM32 know when the FPGA has been 
> programmed?

No (or more correctly, probably not - I have a problem looking at the
details of the signals present in the connector between the Novena and
the STM32 board. But I don't thing FPGA configured signal is routed up
through the connector).

What we could do as a work around is in the FPGA design pulling a GPIO
on the connector high/low and have the STM32 look at that signal. It
would probably take soldering a wire fix on the STM32 board to have this
signal connect to a GPIO on the STM32.


>> The only possible explanation for this behaviuor I found, is item
>> 2.9.4 in STM32F429 errata
> 
> Maybe it's an undocumented errata. How old is the STM32 product?

Full production ramp up was in Q3 2013. The specific errata Pavel is
pointing to is from 2013-02-25 and was added in Rev2 of the errata.

http://www.st.com/web/en/resource/technical/document/errata_sheet/DM00068628.pdf

- -- 
Med vänlig hälsning, Yours

Joachim Strömbergson - Alltid i harmonisk svängning.
========================================================================
 Joachim Strömbergson          Secworks AB          joachim at secworks.se
========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: GPGTools - http://gpgtools.org
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
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=NjE4
-----END PGP SIGNATURE-----