Regarding Boot loader

It is in OTP/ROM at delivery

Hello Manoj,

Bootloader is in the system memory of MCU. by default MCU doesnot execute it. you have to configure the boot pins given.

check here : https://www.st.com/content/ccc/resource/technical/document/application_note/b9/9b/16/3a/12/1e/40/0c/CD00167594.pdf/files/CD00167594.pdf/jcr:content/translations/en.CD00167594.pdf

thank you sir. Sir one more query i have can you please tell me howto send one string "HELLO". using  HAL_CAN_Transmit function i have searched a lot but couldn't get a satisfied answer.

That's not really how CAN functions. You have an 8-byte data payload, you'd need to place your ASCII data within that.

sir can i get one example program of the same ? it will be a great help.

Look at the examples provided in the HAL/Cube trees for the unspecified STM32 part you are using.

...

       /* Set the data to be transmitted */

       TxData[0] = 'H';

       TxData[1] = 'E';

       TxData[2] = 'L';

       TxData[3] = 'L';

       TxData[4] = 'O';

TxHeader.DLC = 5; // Length

       /* Start the Transmission process */

       if (HAL_CAN_AddTxMessage(&CanHandle, &TxHeader, TxData, &TxMailbox) != HAL_OK)

       {

         /* Transmission request Error */

         Error_Handler();

       }