Hello everyone, I used a Nucleo board STM32F429ZI to develop my application. My application uses a Wiz5500 Ethernet module to communicate with another host program and performs some actions based on the received commands.

[Hanni]

The SPI rate is at 21MBit/s and I use STM HAL.

Data rate is high and I receive up to 1 message all 3ms.

After I tested my application I wanted to port it to a G4 to use a cheaper microcontroller.

When using the same code on the Nucleo G474RE and G431RE the SPI connections is not working correctly. After a short and irregular period the SPI interface delivers wrong values.

As example I read 2 bytes RSR register of the Wiz5500 and receive a value around 65000. The value in the RSR register can not exceed 2048 because it is the buffer size.

For G431RB I changed the clock multiplier after PLLM from x85 to x84 and APB1 + 2 Presclater to get the same clock values then F429ZI but the error is still there.

Attached are the settings of SPI1, CS_Pin and Clock Config for both microcontrollers. I checked the wiring three time and I am quite sure that this is not the problem.

F429ZI Clock SettingG431RB Clock Setting 

F429ZI SPI1 Settings and Pins

 

G431RB SPI1 Settings and Pins

 

I think that there is a difference between SPI1 on both boards. The same issue occurs on STM32G474RE.

Please give me a feedback if necessary information is missing.

Thank you for reading this.

Any hint or tipp is highly appreciated.

Best regards

[MM..1]

Check your SPI and CS signals with scope or analyser.