Problem with the ethernet on STM32H743ZI and with core frequency at 400Mhz.

[infoinfo983]

Hi, I have an example that correctly responds to ping 192.168.0.100 on the NUCLO-H743ZI demo board and where the core works at 64Mhz.

If I bring the core to 400Mhz, (only this change), the program no longer works. Why ?

Thank you

Alberto.

PS.I attach complete project and replaced file.

[alister]

Not going to download that project.

Post a snippet of the lines that don't work, your experiments and your observations.

[infoinfo983]

Hello,

The project has been included to give as much information as possible. Nobody is obliged to download it.

The question is the following: if I have that the ethernet works regularly at 64Mhz of cores, and I only change the frequency of the core to 400Mhz, is it normal that the ethernet no longer works?

Do I need to change anything else?

Thank you

[TDK]

The ethernet should function with a 400 MHz clock. Hard to tell what could be wrong without digging into it.

Note that "just" changing the core speed also changes the speed for a lot of other things on the chip.

[infoinfo983]

Hello

You're right changing the core frequency changes many other things, but what bothers the ethernet about this change?

The SysTick_Handler remained at 1mS.

The memory regions, the MPU setting, the LinkerScript.ld, the ethernet and Lwip initialization are identical.

What do you advise me to do?

Thank you

[alister]

>What do you advise me to do?

Perhaps ditch that example software, grab the latest STM32CubeIDE and spin yourself a clean project for your board and start from scratch.

Read community posts daily. That'll teach you what people using the tools or your board/core are struggling with and what works/what doesn't.

Start with something simpler than ethernet your app needs to do, conquer it, then tackle ethernet again (without looking at that bad example).

If you run into trouble, post a concise description to this community what you're using (cube version, h7_fw version, board type, etc, etc), what you're trying to do and what you're observing, and include a few paragraphs from the RM you're reading, and you'll receive good answers fast --- because you'll know more what you're doing and so you'll be able to explain it, and people here will understand it because they're using the same tools and junk too.

There's some information on ethernet with an earlier H7_FW version at https://community.st.com/s/question/0D50X0000C6eNNSSQ2/bug-fixes-stm32h7-ethernet. But don't try to fix it all today. Slow and steady.