[flashrom] Problem while erasing chip prior write bin file.

[Luca Bacci Bonotti]

Thanks a lot. I'll try and I'll let you know.

Il 6 mar 2018 23:13, "Nico Huber" <nico.h at gmx.de> ha scritto:

> On 06.03.2018 22:13, Luca Bacci Bonotti wrote:
> > In your opinion is better the raspberry pi or ch341a to reach my goal?
>
> I don't know. I doubt it makes much of a difference. If one fails, you
> can try the other. Though, the RPi is much faster.
>
> >
> > Should I buy a breadboard for create better connections ?
>
> Better than what?
>
> >
> > Can you draw a schematic that I can follow?
>
> Sigh, I guess I can.
>
> Programmer         SPI Flash
>
>   /CS   ------------  /CS
>
>   MISO  ---50-Ohm---  MISO
>
>   GND   ------------  GND
>
>   MOSI  ------------  MOSI
>
>   CLK   ------------  CLK
>
>   VCC   ------------  VCC
>         \
>          `-10kOhm--- /WP
>           \
>            `-10kOhm- /HOLD
>
> This is about the minimum setup I'd use for a plain (unsoldered)
> chip. Resistor ratings may vary.
>
> Nico
>
> >
> > Il 6 mar 2018 21:55, "Nico Huber" <nico.h at gmx.de> ha scritto:
> >
> >> Hello Luca,
> >>
> >> On 06.03.2018 07:25, Luca Bacci Bonotti wrote:
> >>> I tried with chip soldered and unsoldered. Same results.
> >>
> >> same results? probably due to very different problems. Especially when
> >> the chip is not part of a circuitry (that might already take care), you
> >> have to connect all input pins of the chip. Also, very often, a series
> >> resistor at least on the MISO output is required.
> >>
> >>> I previously tried programming with raspberry PI but it was unable to
> see
> >>> my chip.
> >>> I have both CH341A and Raspberry Pi.
> >>
> >> When you use the Raspberry Pi, make sure you set the `spispeed` parame-
> >> ter of linux_spi to something reasonable (I'd start trying around 1000,
> >> i.e. 1MHz), the default is OS dependent and often not reliable.
> >>
> >>> Where should i connect /HOLD /WP on the CH341A ?
> >>
> >> /HOLD should be pulled up towards VCC (i.e. using a series resistor,
> >> 10kOhm maybe), state of /WP usually only matters when the chip has some
> >> write-protection set up, so either pull up towards VCC or down towards
> >> GND (if in doubt, up).
> >>
> >> Nico
> >>
> >
>
>
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