UART Bootloader for STM32F412VGTx

shanmukhi · ‎2026-01-12

As mentioned in the AN2606 document for STM32F412VGTx MCU(Custom chip), I am using USART2 (PD6/PD5) for UART bootloader using STM32CubeProgrammer. But I am getting an error message as attached. Help me to resolve this issue.

Andrew Neil · ‎2026-01-12

Welcome to the forum.

@shanmukhi wrote:
STM32F412VGTx MCU (Custom chip)

STM32F412VGTx is not a custom chip.

Did you mean STM32F412VGTx on a custom board ?

If so, you need to give details of that board:

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

@shanmukhi wrote:

So have you checked those things?

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.

TDK · ‎2026-01-12

One of these is likely wrong:

Ensure power rails are all connected correctly. All pins.
Ensure VCAP voltage is 1.2 V
Hold BOOT0 high during reset to boot into the bootloader.
Ensure wiring is correct.

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Andrew Neil · ‎2026-01-12

@Andrew Neil wrote:
Did you mean STM32F412VGTx on a custom board ?

If so, is it a known-good commercial product, or your own design?

Have you checked the design against Application note AN4488, "Getting started with STM32F4xxxx MCU hardware development" ?

Has this board ever worked ?

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.