This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DP83849IF: Ethernet is not being Detected

Part Number: DP83849IF
Other Parts Discussed in Thread: MSP430F5529

Hi forum,

we have Made a media converter pcb using DP83849IFVS,

in that ethernet is not detecting when we connect it to the PC..

as mentioned in the schematic only we have implemented.. but the FX cable is also detecting..

the only change what we did is the magnetic.. that to we used the same magnetics (  H1102NL magnetic ) instead of the magnetic implemented in the DP83849IFVS-EVKit suggested in the datasheet..

One of the observation is Ethernet_Link LED is keep on glowing even if we don't connect the ethernet cable.. but FX_LINK is glowing only when i connect the FX cable..

please try to give any suggestions on this.. 

Best regards,

Tex

  • Hi Tex,

    If you are using PoE application, please do have capacitor in the area above to prevent any DC current path between TX+ and TX-, RX+ and RX-.

    --

    Regards,

    Hillman Lin

  • Thanks for the reply Hillman Lin,

    I'm just doing a media conversion.. i belief its just a normal operation.. and took the reference of dp83849ifvs-evk.. still does it required capacitors ???

    also i replaced the H1102 magnetics with H2019 which is taken from the evkit which i purchased..

    One of the observation is Ethernet_Link LED is keep on glowing even if we don't connect the ethernet cable.. but FX_LINK is glowing only when i connect the FX cable..

    Is there any reason behind the ethernet LED On continuously even if we won't connect the ethernet cable.. ???

    Also we implemented only ETH_LINK_LED and FX_LINK_LED.. remaining all we let them float.. Apart from that did as mentioned in the evk schematic..

    Please tell me what are all the IC related circuit settings should i make sure to get the ethernet detected

    NOTE: While i try to monitor ethernet signals observed that from TX pins 60Mhz clk is coming but the RX pins has no signal..

    As per my test results on other link partners and also dp83849evk in the ethernet part these pins would show only 50Hz its nothing but a line signal.. 

    Thanks and regards,

    Tex

  • Hi Tex,

    Sorry for the confusion.

    Schematic looks good to me on MDI lines without the PoE application. One more thing I would like to confirm:

    • Are R18, R19, R20, and R21 are populated with 75 ohms?

    If possible, could you provide a register dump between 0x0000 to 0x001F to observe the current PHY status.

    --

    Regards,

    Hillman Lin

  • Hi Hillman Lin,

    Are R18, R19, R20, and R21 are populated with 75 ohms?

    Yeah! those are populated..

    Could you please share the script and code to upload to msp430f5529..

    also i have doubt on MDIX_EN pin(pin no 2) should i enable it ? 

    i made a ethernet crossover cable and checked if the polarity might be reverse but still the same Ethernet is not detected..

    regards,

    Tex

  • Hi Tex,

    Is your MSP430f5529 flashed? please follow the document session 2.3.1 for flashing instruction:

    We are reading the registers to double check on the current status that PHY is operating in right now and see does the behavior follow the LED behavior.

    MDIX_EN should be enable if you are using cross cable for auto-MDIX feature.

    --

    Regards,

    Hillman Lin

  • Hi Hillman Lin,

    Ethernet detection issue is resolved..

    Reason: Pin number 3 in IC was jumpered high which enabled FX at port A so RJ-45 was not worked..

    Now all the issues are resolved and media conversion also working.. 

    Thanks and regards,

    Tex..