DP83867CR: Establish Link 1Gbit

Hi Richard,

Can you share the register dump that you are seeing when there is no link to the PC?

There could be link issues if you have an unstable clock.

Thanks,

Cecilia

Hi Cecilia,

here is the first block of register map in hex.

R00:1140    R01:7949    R02:2000    R03:A231
R04:0181    R05:0000    R06:0064    R07:2001
R08:0000    R09:0300    R0A:0000    R0F:3000
R10:5048    R11:0002    R12:0000    R13:0000
R14:29C7    R15:0000    R16:0000    R17:0040
R18:0050    R19:4000    R1A:0002    R1E:0002

If you need others registers please let me know this.

Do you mean a unstable clock from the crystal 25MHz?

Thank you very much,

Richard

Hi Richard,

Yes you will need to make sure the crystal at your XI input is within the PPM spec we recommend in our datasheet. 

Is your RGMII clock skewed or aligned? You may need to review that as well since RGMII needs to have a skewed clock.

Thanks

Cecilia

Hi,

I checked the crystal, its 20ppm. To get shure, I changed it to an other one which worked fine in past, but with no working result.

Is a working RGMII interface necessary to get up a link?

I tested on an older design, with no RGMII interface and straps for enabling Autonegotiation, there comes up a link (PC recongnized there is somebody on the end of the line and the LED on Network card is blinking )

In the actual design, with nearly the same configuration nothing works.

Habe you seen any abnormal thing in the register values?

Thank you very much

Hi Richard,

A working RGMII interface is not necessary for the link since this is only the link status on the cable side.it looks like in the register values you've sent, on 0x1, bit 2 it shows that the link is down. 

Is your link partner also set to auto-negotiation? Have you tried testing at a different speed other than 1G and seeing if that works?

Can you also provide your schematic if possible?

Thanks,

Cecilia

The partner is a Win10 PC, and sends autonegotiation pulses. I have measured the pulses on all 4 channels when the ethernet cable is connected.

I don't tested it with other speed settings on PC side.

The schematic is attached below.

Hi Richard,

Your schematic looks to be okay. Can you test and confirm whether the PHY is out of reset by probing on the RESET pin? Can you also check if you see signal on RXCLK? 

That is usually another item we test to confirm functionality on the PHY. 

Thanks,

Cecilia

Reset is probed and ok (2.5V)

RXCLK is 2.5MHz square wave

Thanks a lot

Richard

Hi Richard,

Ok, then it looks like your signals are ok and the PHY is running properly. When you mentioned that you measured the pulses on the 4 channels, what did you see? Could you please share those results with us? If possible can you also share the pulses that the link partner is transmitting as well?

Have you tried connecting two PHYs together on the cable side to see if you can see link? I am trying to isolate the issue to see if we can at least see two PHYs linking together vs PHY + PC. 

Thanks,

Cecilia