[flashrom] Problems flashing N25Q064A13ESE40E SPI chip

[Stefan Tauner]

On Fri, 11 Dec 2015 10:52:38 +0100
Ruben Van de Put <rubenvandeput at gmail.com> wrote:

> Hello,
> 
> I'm having some problems flashing a SPI chip with the BusPirate V3. Writing
> the image is successful but verification is not successful.
> 
> First try with chip on breadboard and long leads (20-25cm):
> http://paste.flashrom.org/view.php?id=2841
> 
> Then I shortened the signal leads and soldered them directly on the
> BusPirate:
> http://paste.flashrom.org/view.php?id=2842
> 
> Then I soldered all leads directly on the chip (with an adapter) instead of
> using a breadboard:
> http://paste.flashrom.org/view.php?id=2844
> 
> I also tried lowering the SPI speed to 1 MHz:
> http://paste.flashrom.org/view.php?id=2845
> 
> Current set-up
> [image: Inline afbeelding 1]
> [image: Inline afbeelding 2]
> 
> Chip datasheet: http://www.farnell.com/datasheets/1674442.pdf
> Flash connected in this way: http://flashrom.org/Bus_Pirate
> 
> Is there anything else I can try or should I try replacing the flash chip?

Hi Ruben,

if you did not give up yet: looks like your changes constantly improved
the situation and you would probably succeed if you just continued to
write the same image a few more times.
One thing that could further improve the communication between the BP
and the flash chip: adding line termination resistors or capacitors as
well as a decoupling capacitor between VCC and GND as near as possible
to the flash chip.
See also https://www.flashrom.org/ISP with some more details even
though the site is directed at other use cases.
-- 
Kind regards/Mit freundlichen Grüßen, Stefan Tauner