Unable to detect the chip after programming

[vbk22398]

 I am programming my STM32F423RHT6. But due to some reason, suddenly I am unable to code the MCU. The connection is getting lost for some reason. I don't know what is the reason for this behavior.  I am attaching my code along with this message. The debugger which I use is an external debugger of stm32. I tried changing TCXO, tried changing the same CHIP. Voltage levels are as per the data sheet. For the 1st few times of programming, am able to flash the code. But after couple of times, facing this issue. 

Note:
I kept programming for peripheral by peripheral and this issue happened suddenly all at once. After finalizing the product and manufacturing parts and soldering, I am facing this issue. Kindly help me out.

Is my chip being dead after few instances of programming?

[Ozone]

As a side note, I don't know the STM32F423RH specifically.

But if you speak about a custom board, consider design-related hardware problems.
Some might manifest only with higher current consumption and/or clock frequency.

[Andrew Neil]

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@Ozone wrote:

if you speak about a custom board, consider design-related hardware problems.

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Indeed.

@vbk22398 Also, if it's the first-produced of a new board, consider manufacturing errors.

[Tesla DeLorean]

Can you connect with BOOT0 pin HIGH ?

Do you have some current limitation on the LEDs?

[vbk22398]

@Andrew Neil Sir added UART Interrupts for UART4 and UART 5. And added an external GPIO Interrupt. Added few mathematical formulas. The ADC was very random and to reduce the fluctuations, wrote some code using math libraries available by default. I did not enable the floating point in MCU/MPU Settings in STM32 Cube IDE even though I used floating point values. But I did all at once without checking it peripheral by peripheral.

[vbk22398]

Sir didn't try that. What should I do sir regarding boot 0 pin. I need de-brick the MCU's.

[Andrew Neil]

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@vbk22398 wrote:

added an external GPIO Interrupt. .

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You didn't use one of the GPIOs used by the SWD ?

[urbito]

I had once an issue regarding:

Which system supply configuration you have on HW? (since for me, your Sch is not very clear)

Then, which one have you put in SW? 

This can let you program your MCU for the first time, but after that first time, it would not boot again until you change it in HW to be as you programmed in SW (in the CubeMX).

Hope this helps.

Greetings

EDIT:

Seems like my guess was wrong, on what to look in, since the capture i posted is for H755 but for F423 there are few similar things that are called: Power Supply Supervisor, that do "the same" as my first guess, and what they do is to check some HW pins and connections with your firmware, as far as i understand at the end the "same thing" is happening, something you have in HW according to the Power Supply Supervisor is in conflict with the SW/FW you have loaded in the MCU, until you make the HW to be the same you have told to the MCU it have when you programmed it, it would not run.

Greetings