DP83867E: It doesn't link with the peer when the speed set on 1000M

Hi,

Please refer to DP83867 debug guide. Some basic check you want to do:


1. Magnetics Used has CT shorted and connected to VCC. DP83867 needs CT connections to be decapped and then connected to ground. Refer to datasheet for schematics.
2. VDD1P0 needs 1V0 while schematics shows connected to 1.2V. Kindly recheck.
3. Straps are configured correclty for 1000M mode
3. Read register 0x00, 0x005 to check the Auto-neg cabilities exchanged

Regards,
Geet

Hi,

I am closing this thread. Incase you still need assistance, please open new thread and provide referennce to this thread.

Regards,
Geet

Hi, thanks for your advices. I've checked the board according to your suggestions step by step as follow:

1.Magnetics CT has been decapped and connected to ground.
2.I've adjusted the VDD1P0 to 1V0
But the chip still cann't work on 1000M after I've made the above changes.
3.There's no straps on board to set the speed, but I've configured the registers through SMI listed bellow:
address 0x1F set as 0x8000,address 0x00 set as 0x1300,address 0x10 set as 0x5068, address 0x09 set as 0x0200, address 0x1F set as 0x4000
Are the above register values correct for Auto-Negotiation with 1000M capable partner?
4.The read back of register 0x00 is what has been written,but the register 0x05 is read as 0x0000.
My DP83867E is still not willing to work at 1000M, please give me more help.
Thank you!

Hi,

Register 0x0005 as 0x000 indicates PHY is not receiving the Auto Negotiation Base page from link partner.

Please dump following register and share with me.

1. 0x0000 to 0x001F
2. Strap Register : 0x006E and 0x006F.


Have you checked the clock frequency on RX_CLK pin ?

Regards,
Geet

Hi,

I am closing this thread. Incase you need further assistance, Please open new thread and provide link to this thread.

Regards,
Geet

I didn't check the registers, because they are not the reason of the 1000M link problem. I solved the problem by postpone the VDD_1P0 power_on time after the VDDA_2P5, and it can work robustly now. Any way, thanks for your advices.