DFU mode read out protection

[Draxter]

Hello, 

I am trying to connect to the STM32F072C8T6 microcontroller via USB in the STM32CubeProgrammer, however I am getting:

"Device is under read out protection ! If you want to disable RDP please reconnect with Read Unprotect enabled"

So, when I check the Read Unprotect (MCU) checkbox, I get:

"Please Power off Power on your device."

After turning the power off/on, I see the same messages. I cannot connect to the MCU via USB in the STM32CubeProgrammer.

I have tried different versions of STM32CubeProgrammer:

• v2.16.0
• v2.15.0
• v.2.13.0
• v.2.10.0
• v.2.8.0

Moreover I tried on second computer with Windows 11 and I have the same issue.

I'm trying to connect my custom board, but I also checked another hardware board (BluePill ) with the same STM32F072C8T6 MCU and it doesn't work either.

Interestingly, using the DFU-util v0.8 program I can connect to the MCU and successfully read/write memory:

 

 

[Amine_Jridi]

Hello @Draxter 

Regarding this issue, we are aware of it and it's currently under investigation.

Internal ticket number: 171192 (This is an internal tracking number and is not accessible or usable by customers).

As a workaround, we suggest connecting your MCU using a HUB instead of plugging it directly into the PC.

Thanks,

Amine.

[new_earth75]

Hello Amine,

Is there any progress on this issue?

I'm using v2.17.0 and I have the same symptoms on my DELL when I plug STM32F0 board on the laptops USB-C ports.

If I use a USB C to A cable on my USB hub, it works. If I use a USB C to A plug converter, then its the same as using a USB C cable.

 

BR

[Draxter]

@new_earth75 answer from STMicroelectronics support:

 

In fact, the issue is coming from the USB bootloader state machine which hangs and stuck in busy state.

This issue is seen only on recent machines with high speed USB controllers, and putting a hub resolves the issue.

Other possible solutions :

- Using dfuse

- Using connectors downgrading the USB speed then putting some more latency in the transmission to make it work

[Draxter]

@Amine_Jridi thank you. Connecting the board to an external USB HUB solves the problem.

 

 

We are unable to understand what is root cause. Why use a USB HUB instead of a direct connection to a computer?

[NeoPete]

Hello,

We also are very interested in the progress in this matter, since we experience the exact same thing. Our hardware though is using the STM32L552. 

[NeoPete]

...I can also add that we've been doing tests on

• Win 10
• Win 11
• Ubuntu

We get the same problem in all 3 environments when connecting the device directly to the computer, but can conclude that in Linux things works much better compared to Windows, but eventually also fails and reboots there. In Windows the problem occurs only on a random set of computers, and most of them are using Win 10, but it does happen on some Win 11 computers as well. On our Linux machines the errors happen more rarely, but they do occur every now and then. 

All in all we get rid of the problem when using a USB-Hub in between the device and the computer. 

[new_earth75]

Yes its quite common on newer machines. The machines that are affected on our side are the ones that support Thunderbold or USB4. I guess the fact that the USB is handled directly by the CPU rather than some chipset with integrated USB hub is the issue.

I asked about this issue in the v2.17.0 release thread but of course there is no answer. The dont aknowledge this in the known issues part of the patch notes either.

I dont care that a USB 2.0 hub solves the issue! Honestly I find distressing that the timings in ST's software rely on the USB controllers latency to work. Man we've got production lines to build and we get this to work with... What's next? Will we need a PS/2 mouse to click on the buttons and a parallel port to remove Write Protection?

My newer machines use dfuse and it seems to work well.

Good luck with yours.

 

 

AT

[remov-b4-flight]

This USB2.0 HUB restriction seems odd

because programmers are not the only people who use STM32Cubeprogrammer.

[Rav K]

Is there an update on this issue? I'm using the latest version of STM32CubeProgrammer and cannot connect to the bootloader without the use of a USB HUB.

[zeboss49]

Hello,

same issue with an STM32F429.

In my project, using a HUB does not solve the issue.
Maybe because the HUB is an USB3 HUB connected to a USB3 port on the PC.

It makes sense if the issue is related to speed.

I'll give a try using an USB2 port and come back to share my experience.

[Draxter]

Hi @zeboss49,

Yes, please try connecting through a USB 2.0 port (or via a USB 2.0 hub connected to a USB 2.0 host).
That would be really helpful for the community to confirm whether the issue is related to USB 3.0 compatibility.

Thanks for checking and sharing your results!

[MMazz.11]

Issue still persisting today: tested CubeProg in both Win11 and Linux Debian 13....

[sam7]

I also experienced this issue, on a STM32F042C4T6 on a custom board. Connecting through a USB hub worked fine.

[davidwbrwn]

Same issue here. Any updates?

I tried using a usb-c to usb-a adapter dongle but that doesn’t work. It’s annoying to have to use an external hub for this. Most laptops have only usb 3.0 ports now, and many have only usb-c ports.

[FBL]

Hi All,

New AN26006 Rev70 released , See Table 36 with Known Limitations :
USB bootloader fails on some machines using a high speed controller. The bootloader is detected. but then data transaction fails.

Root causes:

De-synchronization between USB controller and bootloader SW due to the controller high speed transactions. The controller high speed inter-packet delay seems not sufficient for the bootloader SW (based on interrupt routines) to serve all needed transactions (the delay needed by the BL is nearly 25 µs). Some interrupt services are missed. This results in a communication fail, causing Write command to fail.

Workarounds:

• Add USB HUB between host and the MCU. This relaxes transactions inter-packet delay, and allows the bootloader SW to perform correctly the task.
• Use USB controller/host that increase inter-packet delay.
• For new designs, use DFU in user flash memory to fix the issue.

[davidwbrwn]

I tried an external USB-2.0 hub. It didn’t work. The only thing that worked was to use an ST-Link and Cube Programmer to connect to and flash the device.