Nucleo-F767ZI must reset after power ON

[ManhPham]

Hello everyone, my programme on Nucleo-F767ZI do not run when I power ON by external power supply. I force to press reset button or power supply st-link by usb cable.

I searched some solutions such as: BOOT0 to GND; or turn on bit POR = 1 in RCC_CSR, but nothing worked. 

I don't want to use external circuit to reset.

Anyone can share with me some useful solutions to solve this issue?

[AScha.3]

Hi,

so your nucleo is running, if connecting st-link -> USB ?

But without power on st-link - not ?

Then look , what you get, if st-link not powered:

Clk is coming from st-link , so you have to power the st-link, to get the 8MHz clk, 

or set solder bridges + a crystal connected to F767,

or use only internal HSI clk in your program.

+

Boot0 at gnd , is always needed, if you dont want to start the internal bootloader.

+

NRST has to be separated from st-link, if you dont power it; so power st-link, even if you dont use it - 

or separate the F767 reset from not powered st-link.

Just look at the circuit of your board, to see, what to do .

https://www.st.com/resource/en/schematic_pack/nucleo_144pins_sch.zip

[ManhPham]

Thanks for your advice.

Using clk HSI make the timer run incorrectly in my programme. Best option is supply power for st-link, I don't want to supply through the Micro USB port. 

Could I external supply power for st-link by jumper or other pin ? Which pin, pls help?

[SofLit]

Hello,

Please refer to the UM1974 page 23:

For 3.3V power supply: you need to remove SB3 and SB111 to disconnect ST-LINK from the main MCU because it's keeping resetting it.

[ManhPham]

Sorry no, my external power is 5V, not 3.3V.

So can I remove SB3 and SB111 like 3.3V?

[SofLit · Accepted solution]

---

So can I remove SB3 and SB111 like 3.3V?

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No, so you need to read the first section (VIN/E5V) and apply the described power sequence procedure.

[ManhPham]

Could I supply external power for ST-Link by others pin (not micro USB port), because I need access micro USB port to debug or read log file