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Osman40
Visitor II
November 25, 2025
Question

STM32H723VGT6 not working with DP83848 - HardFault is occurring

  • November 25, 2025
  • 1 reply
  • 168 views

Hello Everyone,

I designed pcb while to use STM32H723VGT6. I used an Ethernet phy called DP83848 to communicate via Ethernet.

I have previously used this Ethernet phy with F4 series processors and communicated via Ethernet without any problems. I am using CubeIDE version 1.18.0. I make the settings from CubeIDE as follows.

  • I am setting RMII mode in ETH from connectivity. I am changing MAC address and i am enabling ethernet global interrupt from NVIC.
  • I am enabling LWIP from Middleware and software Packs. I am disabling DHCP Module and i am setting IP and Subnetmask from general settings. Then I set my phy from platform settings. Only LAN8742 appears in the list.I build the code by selecting this Phy.
  • Then I add the dp83848.c and .h files that I generated for the F4 series to my own project. In ethernetif.c, I replace everything related to LAN8742 with DP83848 functions. All of the functions have the same name. I build the code and no problems occured during the build.
  • I uploaded the code into the processor and saw that phy was working correctly in debug mode. I received no PING messages. After a while HardFault_Handler was occurred. 

    I wrote the following into HARDFAULT_HANDLER:

    uint32_t cfsr = SCB->CFSR;
    uint32_t hfsr = SCB->HFSR;
    uint32_t bfar = SCB->BFAR;
    uint32_t mmfar = SCB->MMFAR;
    and the resulting values ​​are:
    cfsr = 0x400,
    hfsr = 0x40000000,
    bfar = 0,
    mmfar = 0

  • I selected LAN8742, compiled the code, and uploaded it to the processor. No problems occurred. However, the network was down, and I received no PING messages. This was an expected result, as it was the wrong PHY.

I've tried different combinations for a long time, but I haven't found a solution. Can some one tell me if they have got this combo working (H7 and the DP83848), and if so, could you share some working code, please

Thanks,

Osman

 

 

    This topic has been closed for replies.

    1 reply

    L
    LCE
    Graduate II
    November 25, 2025

    Check your driver files.

    Probably some HAL ETH stuff changed since you wrote it for F4?

    I would compare the PHY's datasheets and compare / identify the important registers, then copy the LAN8742 driver files, rename and edit them according to the DP-thingy.

    I would also write some UART debug code to directly read and write the PHY's registers.

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