RMII STM32H743VIT6 Config

[khanhcong861989]

Hi all!

I'm handling project which use communicate RMII TCP/IP. if i set up CPU clock is 200Mhz as picture 1, the system run OK, i can ping network but my system require CPU clock is 400Mhz. if i set up CPU clock is 400Mhz, the connection between board and serve was intermitten. can you help to take alook and share me solution to set CPU clock 400Mhz and can run RMII.

[Pavel A.]

Adjust the wait states for the internal flash so they match the higher CPU clock?

[khanhcong861989]

i ever try ever frequency one by one, it just match highest CPU clock is 200 Mhz.

[Pavel A.]

What is the number of flash wait states in your program at 200 Mhz and at 400 MHz?

[khanhcong861989]

i don't understand yours question but i send you IOC file, can you help take alook it. 

[LCE]

Check the RM what the "eth_clk" source is.

I can only say that for the H723..H735 types, there it is HCLK, which is = CPU / system clock divided by HPRE in RCC_D1CFGR. So for these H7 it can be set e.g. to half of CPU clock.

[STackPointer64 · Accepted solution]

Hello @khanhcong861989, and welcome to ST community!

After inspecting your IOC, I found some crucial missing configurations, such as MPU settings and the LwIP ETH_RX_BUFFER_CNT, which could hinder your project's functionality. I suggest you read through this article and correct the misconfigurations. If the issue persists, we can further investigate the configurations together.

• How to create a project for STM32H7 with Ethernet and LwIP stack working 

Best regards,