STM32F207VCT6 reference schematics

[SAgra.2]

The MCU STM32F207VCT6 reference schematics used in our design is made exactly in the same as NUCLEO reference design except for the feedback resistor for the 8MHz oscillator; our design doesn't have that resistor. MCU doesn't connect via SWD.

*Edited by moderation, please keep the title of your question shorter than 70 characters*

[S.Ma]

First Debug test step: disconnect all clocks going to the mcu, it should use internal one, then check if debug probr works.

[Tesla DeLorean]

The MCU doesn't need an external clock to start or function.

Check voltages at VCAP pins.

Check level of NRST

Check part orientation

Check supplies to VDDA

[Danish1]

The nucleo boards often have a second stm32 microcontroller pre-programmed to act as an ST-Link programmer so you can just plug it into USB and fire up stm32cubeIde.

As you don’t mention this, can I ask do you have an ST-Link (either stand-alone or broken off a genuine Nucleo) that you know works, that you are interfering through?

[SAgra.2]

Yes, I made a PCB following the nucleo f207g reference design and program it through SWD using another ST-Link broken off the same version of nucleo board.

[SAgra.2]

It seems like the reference design does not use the right amount of load capacitances for the oscillators used and hence I am able to program the MCU on PCB through SWD at some random moments and it shows 'target not connected' rest of the time.

Would appreciate any thoughts on the above.