Missing USB CDC Middleware Files After Code Generation (STM32F103C8T6 / Nucleo-F334R8, MDK-ARM)

[choirulafiq29]

Hello everyone,

I'm new to STM32 and currently working on a USB CDC (Virtual COM Port) project using STM32CubeMX with the following setup:

• MCUs/Boards: STM32F103C8T6 and Nucleo-F334R8

• Toolchain / IDE: MDK-ARM (Keil µVision)

• STM32CubeMX versions tested: 6.14.1 and 6.12.1

I configured the USB peripheral in Device Only mode and enabled the Communication Device Class (CDC) in the USB Device middleware settings. I also configured the required USB pins (PA11 as USB_DM and PA12 as USB_DP) and set the USB clock source properly to ensure 48 MHz operation.

However, after generating the project, several key USB middleware source files are missing, such as:

• usbd_core.c

• usbd_ctlreq.c

• usbd_ioreq.c

• usbd_cdc.c

• (and sometimes also usbd_cdc_if.c)

Because of this, the code fails to compile due to missing function references.

---

What I’ve Tried:

• Verified USB pins (PA11, PA12) are configured

• Mode is set to Device_Only

• CDC class is selected in middleware

• USB clock is 48 MHz via PLL

• Enabled code generation options like "Delete previously generated files"

• Completely deleted and regenerated the project multiple times

• Tried both STM32CubeMX 6.14.1 and 6.12.1

• Tried both STM32F103C8T6 and Nucleo-F334R8 as targets

Despite all that, the USB CDC middleware files still fail to appear in the generated code.

---

Additional Note:

I have confirmed that the middleware packages are installed in CubeMX, and I also reinstalled the STM32CubeF1 firmware package just to be sure.

I’m attaching my .ioc file below for reference.

---

My Questions:

• Is this a known issue or limitation with STM32CubeMX when using the MDK-ARM toolchain?

• Is there a manual way to force CubeMX to include the USB middleware files?

• Am I missing any additional configuration step?

Thank you in advance for your help!

 

It's my 2nd day using STM32, i don't know what to do and here's the screenshoot

 

[Mahmoud Ben Romdhane]

Hello @choirulafiq29 ,

 

First let me thank you for posting and welcome to the ST Community.

Your request is under investigation, and I will get back you ASAP.

I suggest also that you provide screenshot of the compilation errors.

 

Thanks.

Mahmoud

[choirulafiq29]

Thanks for your responses, here's the screenshoot of my compiling message error

[Mahmoud Ben Romdhane]

Hello @choirulafiq29 ,

Further to your comment, I reproduced your behavior, and I did not get the compilation errors which you had encountered.

usbd_core.c ; usbd_req.c ; usbd_ioreq.c ; usbd_cdc.c are well generated.

I want to know please the F1 Firmware version.

I will be waiting for your feedback/

Thanks.

Mahmoud