Issue with system memory bootloader

[Anil3]

Hello everyone!!!

By using STM32F401CCU6 controller boot pind and trying to flash my program through UART, for that i have made the Boot_pin0 to high and Boot_pin1 to low and reset the controller later trying to connect with STCube programmer via UART and it's throwing an error everytime as attached in pic. i tried with different baudrates nothing got work. I am using UART2 for connecting with cube programmer.  my final ajenda to custom flash the program without using boot pins but if controller is not working with basic flashing then how can i proceed further?

Before, using the boot pins for jumping to system meory i tried to jumo from application by remaping the SYSCFG register and considering an example shared by one of our community member. then i have found that it is not working later for testing the system memory i tried with the boot pins.

[liaifat85]

You mentioned setting BOOT0 to high and BOOT1 to low. This configuration should indeed select the system memory boot mode, allowing you to connect via UART and flash the device. Double-check the wiring to ensure the BOOT pins are correctly set. After setting the BOOT pins, reset the microcontroller to ensure it enters the correct boot mode.

[Techn]

Remove all connection to the processor. You should be able to get DFU mode working with USB itself. Please refer to the chip datasheet/programming manual

[MM..1]

Are you sure you use right UART2 pins as described in AN2606?

Are your PC bridge UART 3V3 TTL mode ?

[Tesla DeLorean]

What else is connected to the MCU?

Any startup noise on the pins described in AN2606 will result in them being accepted as the connecting party.

It's a one-shot deal, reset and try over if the connection fails at the first attempt.

Is the MCU otherwise tested and functional?

[Anil3]

@Tesla DeLorean 

Thanks for your reply..

What else is connected to the MCU? - I haven't connected any other device except RS232.

It's a one-shot deal, reset and try over if the connection fails at the first attempt. - I have tried for plenty of times but can't able to connect.

Is the MCU otherwise tested and functional? - Yes!! i have tested with a code for which UART2 is working fine.

[Anil3]

@MM..1 

Actually it is mentioned for UART2 Pins are PD5,PD6 but for the controller (STM32F401CCU6) 48 pin package these pins are not avilable instead i have seleted the default pins for UART which are PA2,PA3.

 I am using USB-UART bridge.