It´s possible to program the MC via the virtual COM in a nucleo board like the Nucleo-L4A6ZG?

[RLope.2]

The ST link on the board creates a virtual com port, conected to the LPUSART1 of the micro L4A6ZG.

What I´m trying to do is to program the micro throught this com port. To do this, I try this sequence:

• Put boot0 to high, by shortcircuiting pins 5-7 of CN11
• Push reset button to enter boot
• Try to connect with STM32CubeProgrammer using the option UART, 115200 Parity Even.

Then I can see the packet send by the PC in the TX pin of CN6, but there is no response from the micro. So, a time out message is shown in the log.

When I connect to the board using S-LINK it works correctly.

So, I would like to know if what I´m trying to do is possible, and if yes, what could be the problem?

[Peter BENSCH · Accepted solution]

AN2606 describes the serial channels which can be used for the memory boot mode.

For the STM32L4A6 it gives bootloader ID = 0x93 and lists the channels:

• USART1/USART2/USART3/
• I2C1/I2C2/I2C3/
• CAN1/
• DFU (USB device FS)/
• SPI1/SPI2

There is still no STM32 available in which the bootloader supports LPUART.

Regards

/Peter

[RLope.2]

Thank you very much.

I had misunderstood the datasheet.