topic Re: Mcu cannot receive packets from ethernet in i.MX RT Crossover MCUs

Mcu cannot receive packets from ethernet

goodboy2024 — Tue, 15 Dec 2020 07:38:54 GMT

Hello,I use imxrt1061 in my project.Sometimes I meet the problem that my board cannot receive any packets from ethernet.After the board powers up,it can work well.It has LWIP protocol and we can ping from computer to board.After a while,occasionally,we find ping is error.I dump some register values as attached.You can see RMON_R_PACKETS(402D8284): 0000121E and IEEE_R_FRAME_OK(402D82CC): 0000121D.These two register values arenot equal.I think it is abnormal.

Can you explain the meaning of these two register and the reason they arenot equal.Thank you a lot.

Re: Mcu cannot receive packets from ethernet

danielchen — Tue, 15 Dec 2020 08:34:17 GMT

RMON_R_PACKETS： Rx packet count statistics register

IEEE_R_FRAME_OK: Frames received OK statistics register.

It means packets missed during receiving.

Which RAM is the first RAM in your project? can you dump your memory details?

Regards

Daniel

Re: Mcu cannot receive packets from ethernet

goodboy2024 — Tue, 15 Dec 2020 08:40:13 GMT

Attached is project build link file.

Re: Mcu cannot receive packets from ethernet

danielchen — Tue, 15 Dec 2020 08:49:23 GMT

Please also check your global data placement, if you place global data to OCRAM, it will result in packets missing.

Regards

Daniel

Re: Mcu cannot receive packets from ethernet

goodboy2024 — Fri, 18 Dec 2020 05:26:50 GMT

All global data cannot be placed on OCRAM ?Could you give me some more detail explanation about it?

Thanks a lot

Re: Mcu cannot receive packets from ethernet

danielchen — Fri, 18 Dec 2020 05:49:58 GMT

To make more accurate, the enet descriptor and enet buffer need to be placed in a NON-CACHEABLE region. DTCM is a non cacheable region.

in enet_etherentif_kinetis.c

AT_NONCACHEABLE_SECTION_ALIGN(static enet_rx_bd_struct_t rxBuffDescrip_0[ENET_RXBD_NUM], FSL_ENET_BUFF_ALIGNMENT);
AT_NONCACHEABLE_SECTION_ALIGN(static enet_tx_bd_struct_t txBuffDescrip_0[ENET_TXBD_NUM], FSL_ENET_BUFF_ALIGNMENT);
SDK_ALIGN(static rx_buffer_t rxDataBuff_0[ENET_RXBD_NUM], FSL_ENET_BUFF_ALIGNMENT);
SDK_ALIGN(static tx_buffer_t txDataBuff_0[ENET_TXBD_NUM], FSL_ENET_BUFF_ALIGNMENT);

Regards

Daniel

Re: Mcu cannot receive packets from ethernet

goodboy2024 — Fri, 18 Dec 2020 08:12:16 GMT

I notice your examlpe code:

SDK_ALIGN(static rx_buffer_t rxDataBuff_0[ENET_RXBD_NUM], FSL_ENET_BUFF_ALIGNMENT);
SDK_ALIGN(static tx_buffer_t txDataBuff_0[ENET_TXBD_NUM], FSL_ENET_BUFF_ALIGNMENT);

it doesnot have AT_NONCACHEABLE_SECTION_ALIGN ahead

Re: Mcu cannot receive packets from ethernet

danielchen — Fri, 18 Dec 2020 08:16:46 GMT

They should be put to NON-CACHEBALE region according to my test.

Re: Mcu cannot receive packets from ethernet

danielchen — Fri, 18 Dec 2020 11:43:38 GMT

It should be

AT_NONCACHEABLE_SECTION_ALIGN(static rx_buffer_t rxDataBuff_0[ENET_RXBD_NUM], FSL_ENET_BUFF_ALIGNMENT);
AT_NONCACHEABLE_SECTION_ALIGN(static tx_buffer_t txDataBuff_0[ENET_TXBD_NUM], FSL_ENET_BUFF_ALIGNMENT);

Re: Mcu cannot receive packets from ethernet

goodboy2024 — Mon, 21 Dec 2020 05:39:12 GMT

Hi,Daniel:

Thanks for your reply.As we known,the ethernet driver code is from nxp.I want to know whether the official code has been changed like that.

Besides,according to ocram_dma.jpg,DMA visits ocram more effectively than TCAM

Re: Mcu cannot receive packets from ethernet

danielchen — Tue, 22 Dec 2020 06:33:00 GMT

The official code put the rx/tx buffers into the DTCM. I will issue a ticket to the software team.

Regards

Daniel