Hi Nikhilraj,

Thank you for submitting your query and attaching the schematic. I am not sure if I am fully understanding the desired operational mode. What is the desired mode? Are we using the 869 as a Fiber to copper Media Converter? Could you provide a block diagram of the system?

If the customer has register access, we can read a few Registers to confirm the strap settings and operational mode (Reg 0x6E & 0x1DF). Please see section 2.1 Configuring Correct Operational Mode in the DP83869 Troubleshooting guide for more information.

Regards,

Alvaro

Hi Alvaro, 

Thank you for the resposnse

We are interfacing 869  with AM6442 Sitara processor via RGMII  . Basically it is fiber (SFP) to Copper  converter.  

How to read the registers ? In design JTAG provision is added for  for 869 .

regards, 

Nikhil

Hi Alvaro,

Please see the below block diagram  of our testing set up . 

these are the register values we are getting 

reg:0x6e val:0x00d2
reg:0x1df val:0000

Hi Nikhilraj,

Thank you for the block diagram, could you confirm what port in the block diagram the DP83869 is in? If it is Ethernet Port 2, from my understanding based off the schematic your connection looks like:

AM6442 <-RGMII-> DP83869HM <-Fiber-> SFP Module

Nikhilraj KB said:

reg:0x1df val:0000

This tells me you are in RGMII-to-Copper mode. This is not the mode you want to be in, from the schematic I can see that the copper pins (TD_P/M_[A..D]) are left floating. Instead you have the the fiber pins (SIP/SIN & SOP/SON) connected. You should be configured into RGMII-to-100Base-FX or RGMII-to-1000Base-X, depending on the desired speed.

You can change the OPMODE via registers, please try the following script, found in Section 7.4.8 Register Configuration for Operational Modes of the data sheet.

Regards,

Alvaro

hi Alvaro,

We had already tried the register settings apart from the strap configuration, but after reset command register, the register 0x1df came back to 0.

Hi Nikhilraj,

Either the register write you did to 0x1DF didn't stick or something is overwriting this register. Please note that Register 0x1DF is an extended register, please see this FAQ for more information.

Regards,

Alvaro