DP83640: Ethernet Link status

Hello,

Could you provide register values from 0x00 to 0x1F, 0x6E and 0x6F?

Sincerely,

Gerome

Gerome,

I have attached document of register values for your reference.

Attached document is without loopback.

Another thing, yesterday after enabling loopback bit in BMCR then link status is coming 1 and led link had glowed. 

register_values.pdf

Regards,

Gaurav

Hello,

I will need some time to gather information regarding this. I expect to get back to you by next week.

Sincerely,

Gerome

Gerome,

Ok. 

Try to resolve my problem as early as possible.

Regards,

Gaurav

Hello,

To answer some of your previous questions:

For Completing auto negotiation link should be established, right?

- Yes, link should be established.

Do I need to configure IC to established the link? 

- No, as long as you are bootstrapped correctly.

Can you send some scope captures of the signal on the MDI pins? What is the link partner you are using, and have you tried using a known good link partner?

Sincerely,

Gerome

Gerome,

I am attaching scope captures of MDIO clock pin and MDIO data pin.

I have attached PHY chip schematic in 1st post. Could you please check bootstrapped? I have connected ethernet cable to this PHY chip and on other end to my desktop. In my desktop RJ45 port is working port.

Currently no application code is there in flash memory so when I power on the board then link should be established. If link has been established then only I can proceed for the code, right?

Regards,

Gaurav

Hello Gaurav,

The registers looked okay. I would like to move the focus onto the RJ-45 section. I don't see that schematic in the file you sent me, but can you probe for MDI signals off of the RJ-45 cable? You should be seeing auto-negotiation pulses when the other side of the cable is connected to the PHY, and vise versa if you plug part of the cable into your PC and probe off the other side.

Also, can you confirm that the signal on pins 42-46 are going into high impedance pins on the MAC? 

Another note, your current limiting resistors for your LED's seem a little high. I would suggest using 165 Ohm resistors as current limiting resistors. For your parallel resistor on pin 27, the 2.2kOHM value is fine.

Sincerely,

Gerome

Gerome,

I have enabled loopback bit in BMCR then link status is coming 1 and led link had glowed. From this, what can I conlude?

BIST is coming pass.

Can I do BIST with external loopback? If yes, what changes I need to do?

After initialization  MDIO from processor side then pulses are coming on MDIO pin no. 30 as you can see in shared scope pictures in previous post.

For link establishing, pulses will come on TX+/- & RX+/- pins as I power on the board, right?

PHY chip should be in RMII master mode or slave mode?

Is this hardware problem or software configuration problem?  Can I get some reference code for this IC?

Regards,

Gaurav

Hi Gaurav,

Thank you for the BIST information. I will have to talk with the team to figure out these questions. I should have a response by Tuesday next week.

Sincerely,

Gerome

Gerome,

Ok.

Regards,

Gaurav

Hi Gaurav,

Thank you for the information regarding sending the PHY in loopback mode. I had some questions regarding how you were able to establish link through setting loopback:

1) When setting loopback, did you disable the auto-negotiation functionality as described in section 5.3.5?

2) If the answer to 1 is "yes", is the original link partner's autonegotiation settings disabled?

3) If you connect two DP83640 PHYs together, do you get link?

4) What settings are you implementing for the BIST?

"Can I do BIST with external loopback? If yes, what changes I need to do?"

- Yes, you can do BIST with external loopback. The PHY can work under normal operating conditions. There are no extra software configurations needed for this, but you will need to do some reconfiguring on the cable side. More information on this is posted here: e2e.ti.com/.../1170648

"For link establishing, pulses will come on TX+/- & RX+/- pins as I power on the board, right?"

- Yes, the pulses will come on these pins.

"PHY chip should be in RMII master mode or slave mode?"

- The PHY should be in RMII master mode if doing loopback.

Sincerely,

Gerome

Hello Gaurav,

Glad to hear that link has been established! Driver code is located at this link: https://www.ti.com/tool/ETHERNET-SW. 

Sincerely,

Gerome