FAQs
cancel
Turn on suggestions
Auto-suggest helps you quickly narrow down your search results by suggesting possible matches as you type.
Showing results for 
Search instead for 
Did you mean: 

My Custom STM32 Board Boots Only After Pressing Reset

eva_402
Associate II

‎2026-04-27 1:02 AM - last edited on ‎2026-04-30 2:13 AM by

Hi all,
I designed a custom STM32 board that powers up, but the firmware starts only after I manually press the reset button. Once reset is pressed, everything works normally.

The clock source is an external crystal, and BOOT pins are configured with resistors.

Questions:

  1. Should I suspect reset timing, clock startup, or BOOT pin state first?
  2. Would increasing reset delay with an RC network help?
  3. On the PCB, how close should crystal traces and load capacitors be placed to the MCU pins?
Labels:
0 Kudos
2 REPLIES 2
mƎALLEm
ST Employee

‎2026-04-27 1:41 AM

Hello,

What MCU part number you are using?

You should always provide the MCU part number when posting a question related to STM32.

To give better visibility on the answered topics, please click on "Accept as Solution" on the reply which solved your issue or answered your question.
Andrew Neil
Super User

‎2026-04-27 1:52 AM

As it's a custom board, you need to show its schematic - we have no other way to see it!

How to write your question to maximize your chances to find a solution

 

@eva_402 wrote:

BOOT pins are configured with resistors.

How, exactly, are they configured?

 

Have you studied application note AN5673, Getting started with STM32C0 MCU hardware development ?

A complex system that works is invariably found to have evolved from a simple system that worked.
A complex system designed from scratch never works and cannot be patched up to make it work.
Top