DP83869HM: Link is up but not able to ping

Derryl Tauro

Part Number: DP83869HM

Hi,

We are using DP83869HM in RGMII to copper mode with auto-negotiation enabled. RGMII side is connected to Xilinx Zynq PS. HW straps configured to 1000Mbps. We are debugging through u-boot using mii utility.

Please refer to the PHY register values

reg 0x0-->0x1140

reg 0x1-->0x796D

reg 0x9-->0x0300

reg 0x10 --> 0x5048

reg 0x1f --> 0x0000

reg 0x1df (opcode mode register) appears to be 0xffff. On writing to the register using mii write, value appears to be same.

We tried disabling auto-negotiation, reducing the speed to 10Mbps & 100Mbps on both link partner and phy. We are still not able to ping.

Expecting your help in resolving the issue.

Regards,

Derryl

over 3 years ago

0 Gerome Cacho over 3 years ago

TI__Mastermind 39855 points

Hello Derryl,

The issue here is on the MII side, not the MDI side. Auto-negotiation and speed changing between PHY and LP will not help as the issue is on a different part of the PHY. I would suggest taking a look at Reg 0x86 to adjust RGMII skew to find a working combination.

Sincerely,

Gerome

0 Derryl Tauro over 3 years ago in reply to Gerome Cacho

Prodigy 20 points

Hi Gerome,

Thanks for your inputs. We will have a look at the register 0x86 to adjust RGMII skew. We had an observation, after disabling the auto-negotiation (writing 0x100 in Reg 0x0) the status of auto-negotiation was still shown enabled( Reg 0x1, bit[3], val=0x1). What could be the reason for this?

0 Gerome Cacho over 3 years ago in reply to Derryl Tauro

TI__Mastermind 39855 points

Hi Derryl,

If you did a software restart of the PHY, would this bit change? (Reg 0x1F[14] = '1')

Could you also look at Reg 0x11[11]?

Sincerely,

Gerome

0 Derryl Tauro over 3 years ago in reply to Gerome Cacho

Prodigy 20 points

Hi Gerome,

Default value of Reg 0x1F = 0; and what ever the values we are writing into that register is not reflecting back, always the value is 0.

Reg 0x11 = 7F02;

0 Gerome Cacho over 3 years ago in reply to Derryl Tauro

TI__Mastermind 39855 points

Hi Derryl,

Regarding Reg 0x1F, this is normal behavior for the PHY. It will self-clear.

To see effects of auto-negotiation disabling, please connect a known good link partner (LP) to PHY and check for a link (Reg 0x1[2] = '1'). Afterwards, try disabling auto-negotiation by writing Reg 0x0[12] = '0' and try disconnecting and reconnecting Link Partner.

Sincerely,

Gerome

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DP83869HM: Link is up but not able to ping