Ethernet dropped packets

[Julian Winpenny]

Posted on July 18, 2017 at 12:05

Hi,

Using STM32CubeMx version 4.21.0 for STM32F765VG with KSZ8081RNA ethernet PHY (RMII mode).

Ethernet is painfully slow. Received packets are dropped and transmit packets are somehow also lost.

Does anyone have any guidelines that might help fix the issue please?

[Imen.D]

Posted on July 18, 2017 at 13:08

Hello

Winpenny.Julian

,

You'll probably want to review Ethernet example within STM32CubeF7 v1.7.0. and

http://www.st.com/content/ccc/resource/technical/document/user_manual/79/6e/5f/d4/5c/25/43/96/DM00103pdf/files/DM00103pdf/jcr:content/translations/en.DM00103pdf

, it maybe helpful as it provides a full description of how to implement In-Application Programming (IAP) using Ethernet communication.

Have a look to theerrata sheet related to your device, in the section 'Ethernet peripheral limitations' to check if you have the same conditions as described in the errata sheet.

With Regards

Imen

[waclawek.jan]

Posted on July 18, 2017 at 13:40

50MHz is not a trivial clock frequency... Clock arrangement, ETH signals layout, RMII signals layout - all this comes into play.

JW

[Julian Winpenny]

Posted on July 18, 2017 at 16:06

Interestingly after updating STM32CubMx to version 4.22.0 my test dump of the PHY registers failed.

Enabling pull-ups on MDIO / MDC fixed that issue. So there could very well be a slew-rate issue with the signals.