How to make Read out protection on NUCLEO-144/F429ZI with STM32CubeProgrammer without USART error.

[DAhn.1]

we installed an application binary on NUCLEO-144/F429ZI with UART2 as an external interface and USB-UART for debugger.

And the binary code been downloaded via the debugger port using STM32CubeProgramer with the tool option of "STM32CubeProgramer(SWD)" and "USB support(if possible): None"

It goes well without readout protection of OB(Option Byte). Also well in serial out on USB-USART.

By the way, once Read out protection was set to 'BB' from 'AA', it will not go well. no output on USB-UART.

What's my misunderstanding on the Readout protection?

[Sara BEN HADJ YAHYA]

Hello @DAhn.1​ ,

Thanks for your feedback,

To avoid any misundrestanding, let me share with you my comprehension: Are you trying to load a binary file on your board when Readout protection is set to BB and the device is connected via STLink?

If not could you please clarify more the issue ?

Sara.

[DAhn.1]

Thanks for your reply.

I loaded a binary first on my board and verified its work well.

This means that a hyper terminal linked to debugger port shows the text message what I want to print.

And then I set readout protection to "BB" in OB(option byte).

After the protection set to "BB", no message responses displayed on the terminal,

DAhn.

[Pavel A.]

When you change RDP from BB (level 1) to AA (level 0), your program gets erased and cannot print anything. This is the normal expected behavior.

[Sara BEN HADJ YAHYA]

Hello @DAhn.1​ ,

Thanks for the clarification,

After setting RDP to "BB", the device requires a Power OFF/ Power ON to re-start the application. Please try to unplug your board after setting RDP and then re-connect it.

Let me know if this helps!

Sara.

[DAhn.1]

It's OK and solved my problem with your advice.

So far I reset using only reset button on the board.

that's my problem.

Thank you again. Sara.

DAhn.