How to solve the problem of flash write protection in STM32?

This paper introduces how to solve STM32 chip Flash The program cannot be downloaded due to write protection , Problems that cannot be debugged online ; If you have the same problem , I hope this article can help ;

First of all, let me give you some tutorial materials , I hope it will be helpful for you to learn ,
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1 FLASH Write protection for

If the Flash Write protection is set , Then there's no way to Flash Programming and erasing .

Developing STM32 When , If that happens , In general, simulators support Flash To unlock , image jlink,stlink And other emulators support this function .

2 Error message

In the use of MDK When debugging , There is an error Flash Timeout.Reset Target and try it again, The details are shown in the following figure ;

After some tossing , It didn't solve the problem , Because the simulator used is stlink, So I downloaded stlink utility Try to solve the problem ;

3 stlink utility
3.1 Basic function

stlink utility yes ST Official free software , Support STM32 ST-LINK The program includes a command line interface （CLI） The graphical user interface （GUI）. The tool also provides many other functions , As follows ;

It can be done to STM32 Internal memory （Flash,RAM,OTP And other memories ）, Programming with external memory ;
Verify program content （ The checksum , Check during and after programming , Compare with documents, etc ）
Also can realize STM32 Programming Automation ;
There are other functions ;

3.2 Unlock Flash
stay stlink With the target board connected , open stlink utility, On the menu bar Target Choose connect, Because at this time Flash It's locked , So also see the corresponding error prompt Can not read memory Disable Read Out Protection and retry, The details are shown in the following figure ;

OK, Next, just touch write protection , So in the menu bar target Open in Option Bytes… Options , Or directly through the shortcut keys ctrl+B open , Please make sure that you are currently connected properly stlink And target board , Otherwise, an error will be reported ;

With the right connection , open Option Bytes…, Found here Read Out Protection The options are enable, This expression can't pass swd Read STM32 Inside Flash The program .

Key points ： take Read Out Protection Option set to disable, Click on Apply, Now Flash It has been successfully unlocked . But at the same time , Inside Flash It has been erased ;

This may be possible. STM32 It's about the protection mechanism of , Prevent programs from being copied , Then decompile and crack it , This can also raise the threshold of cracking . The specific display is shown in the figure below ;

After completing the above steps , In the menu bar Target Choose Disconnect, Or through the shortcut keys ctrl+D Disconnect from the target board ; Re enter MDK, The target board can be debugged normally , Simulation , And the burning of the program .

3.3 Write protect

In the menu bar target Open in Option Bytes… Options , We also see that there are Flash sector protection Options ; choice Select all after , Find out all Page It's all protected , Just choose apply Options can be used to Flash Write protect ; The details are as follows ;

4 summary
about Flash The problem of write protection can be combined with STM32 Refer to the manual for corresponding study , Its internal Flash Provide corresponding protection mechanism , This article is just a combination of ST Official tools stlink utility Solve the common simple problem .