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stm32f4-discovery - unknown chip id! 0xe0042000 #107

jpmzometa opened this Issue Sep 1, 2012 · 21 comments

Hi, i have a problem similar as #issue 64, but with a STM32F4-DISCOVERY.

st-flash write build/ch.bin 0x8000000

2012-09-01T18:33:59 INFO src/stlink-usb.c: -- exit_dfu_mode
2012-09-01T18:33:59 INFO src/stlink-common.c: Loading device parameters....
2012-09-01T18:33:59 WARN src/stlink-common.c: unknown chip id! 0xe0042000
stlink_sram_flash() == -1

Any hints?



Have a look here:

"Connect under Reset" technique in STM-32 ST-LINK Utility brought back my dead mcus.


Nomados commented Mar 30, 2013

I have the same problem!


To get back in touch with the chip, I have to boot into Windows and use the STM-32 ST-LINK Utility from ST to erase the flash with "Connect under Reset" enabled in Settings.

kyab commented Jul 15, 2013

I have the same problem but now it comes back with STM-32 ST-LINK Utility on Windows. Thanks!

perexg commented Jan 1, 2014

You can also short the BOOT0 pin with the VDD pin (using a jumper) to select the system memory (DFU bootloader) as the boot mode. Quick and simple.


@perexg That does not work.

elpaso commented Sep 24, 2014

@tghosgor works for me...

latsku commented Oct 29, 2014

What worked for me was:
1. Short the BOOT0 pin with VDD
2. Reset the board
3. st-flash erase

@fnack fnack referenced this issue in RIOT-OS/RIOT Jan 6, 2015

cpu/stm32f4: Add LPM implementation #2246


Thanks @latsku, that worked perfectly.


@latsku yes, your 3 steps worked for me too. Thanks!

ADARSHBU commented Jun 3, 2015

Hi Latsku,

Great buddy, those 3 steps works fine for me ....
Thank you..


@latsku thank you very much for your suggestion! This helped me as well.


Tried all suggestions but still get WARN src/stlink-common.c: unknown chip id! 0xe0042000


@ADARSHBU it's a link to the current page

ogzarm commented Dec 23, 2015 Stm32 St-link utility application
2.Target>Settings mode should be Connect Under Reset
3.Full erase chip
it is okey.


@latsku im very new in stlink and boards, so sorry for the dumb question but, what does "1. Short the BOOT0 pin with VDD" really mean?

latsku commented Jan 27, 2016

@polaroi8d Not a dump question at all.
Connect the BOOT0 pin with the VDD pin.

And the electronics slang part. Short comes from short circuit, which is connecting the pins with a wire or similar conductor.


@latsku Okey, thanks for the answer, its woorking :)

tcurdt commented Apr 9, 2016

So far I have just connected the ST-LINK V2 (with no board connected) and then ran st-util which gave the rc/stlink-common.c: unknown chip id! 0xe0042000 which let me here.

Now is this because there is no board connected?
Or is this about the ST-LINKV2 itself?
Or what is it?

I still have to try the above instructions on how to fix this - but could someone try to explain what the problem actually is? I didn't get it from the above comments yet.

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