STM32F107 + DP83848(Ethernet controller)

infoinfo973 · ‎2011-09-01

Posted on September 01, 2011 at 10:37

Hello,

I have a problem with the ethernet controller DP83848 in combiantion with a STM32F107. I designed a PCB with these two components, I copied a part of the schematic of the STM3210C-EVAL board. I am using the RMII mode so I didn't connect the lines needed for MII. I know the software works because I tested it with the EVAL board. I suspect that the ethernet controller works because I can read and write to it. My problem is that I am getting a lot of false carrier sense errors from the ethernetcontroller so I think it has something to do with receiving data over ethernet. Does anybody have any experience with this problem or the ethernetcontroller?

Thank You,

Marco

#metoo #stm32f107-dp83848-carrier-sense #rmii

Tesla DeLorean · ‎2011-09-01

Posted on September 01, 2011 at 14:43

Verify the values of the actually placed components. Double check any parts on the eval schematic for fit/no-fit indications, and against the BOM.

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infoinfo989 · ‎2011-09-01

Posted on September 02, 2011 at 05:27

Check your transformer and RJ45 connector wiring / pinouts, particularly if you're not using the exact same parts as the eval board. I personally find those components to be the easiest to mess up.

infoinfo973 · ‎2011-09-02

Posted on September 02, 2011 at 11:04

Thank you for your reply. I used the same parts as in the EVAL board, I only added some ferrite beads to the 3V3 lines. In the schematic of the EVAL they used 50 ohm resistors for the TD+- and RD+- lines but they fitted 51 ohm and I am using also 51 ohm.

I am using the same connector and same values for the resistors.

infoinfo973 · ‎2011-09-02

Posted on September 02, 2011 at 11:09

Maybe someone can see something wrong with my schematic.

________________

Attachments :

Ethernet.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I0rb&d=%2Fa%2F0X0000000bec%2FEHMW.Tc570Se6QAirZDkyCZ4wihF4TaSHuqvzuCVrlk&asPdf=false

ocey · ‎2011-09-08

Posted on September 08, 2011 at 16:33

I have exactly the same problem, with basically the same schematic. I used the primary source (J0011D21B) jack, and did not include the ferrite beads. The rest of the schematic is identical. If I find the answer, I will let you know.

martijn23 · ‎2012-03-22

Posted on March 22, 2012 at 11:29

Hello,

Did you, by any change, solve this issue?

I'm expiriencing the same problem.

Thanks,

Martijn

alok472 · ‎2012-03-24

Posted on March 25, 2012 at 04:28

for RMII mode, i guess we need to use 50MHz. In the Schm attached, i see a comment related to 25Mhz. Hope this is taken care.

amin23 · ‎2012-03-26

Posted on March 26, 2012 at 15:14

Hello,

Try to clock the PHY using Ext. oscillator; for RMII mode, user have to provide the 50 MHz clock by soldering a 50 MHz oscillator (ref SM7745HEV-50.0M or equivalent) on the U3 footprint located under CN3 and also removing jumper on JP5. This oscillator is not provided with the board. For more details, please refer to STM3220G-EVAL evaluation board User manual (UM1057).

alok472 · ‎2012-03-27

Posted on March 28, 2012 at 03:57

Hi Martijn

Can you pls confirm if this solves your problem ? i hope yes.