Experiences with Non original STM32F4 processors from China.

[LKone.1]

Hello everybody, we use STM32F429 processor in our devices. In the current lack of chips, we were forced to order chips from the only supplier who had them in stock, from China. The processor seems to work, but unfortunately it cannot be loaded other than via STLink (USB DFU, USART, I2C loading does not work). When reading the device electronic Signature values from the memory, it seems that "something is wrong". The BOOTLOADER version is not filled in, also the size of the FLASH memory. I want to ask if you have a similar experience?

[Uwe Bonnes]

Is your design tested with a working board of same revision with a CPU you suspect genuine? Did you test multiple boards? If not, I would expect hardware problems. The marking seems genuine.

[LKone.1]

Yes, I have tried older series processors on the same boards and they work properly. No change on the boards, only these processors. In the appendix, I enclose a table regarding the BOOTLOADER ID, a memory dump from an older revision of the processor and the Chinese one.

original:

Chinese:

 

[Peter BENSCH]

No, the marking looks anything but original: the letters do not match the original, the digits are all different, the logos are very badly faked, etc.

No wonder that the device does not behave as expected. You could do an xray of an original and these fakes, you will be surprised.

Regards

/Peter

[LKone.1]

I took a picture of Chinese and original chip. Here it is:

[S.Ma]

Read the 96 bit chip id which contains the lot, dice position in the wafer, etc...

Also try to use stlinkv3. This will provide additionnal traceability.

[LKone.1]

this is 96 bit chip ID memory dump. Look at the address 0x1FFF7A22 (Flash size). Due to ST documentation this address cointains the flash size. The value for STM32F429VGT6 must be 0x400.