cubemx project

[Syang.2]

I use cubeMX version6.0.0，generate a simple serial port project, I need to click three times 'run' can run to the main function(break point) use jlink in debug mode ,

The serial port tool has output character,. But direct download and re power-on does not work.

Self-made board: stm32f446ret, other projects(mbed os) can be downloaded and run directly. In debug mode, only need to press run once, there is no problem with the board

[TDK]

> Self-made board: stm32f446ret

> there is no problem with the board

Maybe you're right, but the simplest explanation is BOOT0 isn't pulled down, or some other hardware issue. If you give the STM32F4 power, it will run the code in flash memory, barring special cases like NRST held low or SWD halting the core.

[Syang.2]

Confirmed BOOT0 is pulled down.how to confirmed special cases like NRST held low or SWD halting the core on my project?

[TDK]

Use a multimeter to measure NRST and disconnect the debugger before power cycling.

[Syang.2]

I disconnect the debugger and power-on, measure NRST from low to high