STM32F207ZG: Does the LWIP/Ethernet device require a DMA?

[Nicholas Hemstreet]

Posted on June 15, 2018 at 18:24

I'm attempting to get UDP working on the STM32F207ZG with the RMII Ethernet interface and Lwip as TCP/IP stack and without a RTOS. I've followed an old guide I found for the STM32F4 modifying the CubeMX generated driver files as needed and am just trying to confirm I generated the right files.

As it stands I configured the RMII interface in CubeMX without a DMA attached (which I thought was fine), but when I send data to the device (I'm not sure how to make sure that it is indeed connected to the correct IP. The netif says it is up, but I'm unsure how useful that is) the HAL_ETH_GetReceived_Frame (which is what I followed the execution of ethernetif_input to) seems to check if the current segment is not owned by a DMA via this line:

if(((heth->RxDesc->Status & ETH_DMARXDESC_OWN) == (uint32_t)RESET))

Does this mean I must have a DMA connected to the RMII interface so I can read the frames? What is the above line doing? Are there anymore recent applications for the STM32F2 Nucleo board which I could use to work backword and figure out how this all works?

Any input/advice/hints/criticism is welcome.

Thanks,

Nic.

#ethernet/ip #raw-lwip #beginner #stm32f2 #ethernet

[Imen.D]

Posted on June 18, 2018 at 12:05

Hello

nickhemstreet

,

May be you should have a look to the errata sheet related to the

http://www.st.com/content/ccc/resource/technical/document/errata_sheet/79/08/a3/cc/fa/5c/49/c5/DM00027pdf/files/DM00027pdf/jcr:content/translations/en.DM00027pdf

devices, in the section 'Ethernet peripheral limitations'and check if your issue is related to the know limitations.

You'll probably want to review LwIP examples as you can find available in the STM32CubeF2 package:

STM32Cube_FW_F2_V1.7.0\Projects\STM32F207ZG-Nucleo\Applications\LwIP, It can help you as an implementation example to develop your own application.

With Regards,

Imen

[Nicholas Hemstreet]

Posted on June 20, 2018 at 17:22

I looked in the limitations and checked the schematic, but found no mention of the problem. I was hoping that there was a best practices guide or something along those lines.