DP83822IF: Cannot link with gigabit Ethernet port of PC

John11513

Part Number: DP83822IF

Hi,

My customer reported an issue with DP83822IF: it cannot link with PC's gigabit ethernet port.

The device is connected to MAC through RGMII, 25MHz crystal, pure pin strap configured as: pin RX_ER (RH=6.2K, RL=1.96K), CRS (RH=13K, RL=1.96K), all other strap pins open.

Now, the device can be correctly linked to 10/100M Ethernet, while cannot linked to 10/100/1000M Ethernet. We checked the RGMII interface clock frequency and found it was actually configured as 10Mbps mode (2.5MHz clk frequency) when connected to gigabit ethernet. When connected to 10/100M Ethernet we found the interface clock is configured to 25MHz and the link is correct. Why? how to fix this issue?

Thank you!

John

over 2 years ago

0 Adrian Kam over 2 years ago

TI__Expert 5425 points

Hi John,

The DP83822 does not support gigabit Ethernet, only 10/100M. When the device is connected to the 10/100/1000M ethernet port, is there no link for 10/100M speeds for that port?

Regards,

Adrian Kam

0 John11513 over 2 years ago in reply to Adrian Kam

TI__Expert 5360 points

Hi Adrian,

Yes, there no link for 10/100M speeds.

Yes i understand DP83822 does not support gigabit, while gigabit ethernet can support 10/100M link. Why they cannot establish 10/100M link?

Thank you!

John

0 Adrian Kam over 2 years ago in reply to John11513

TI__Expert 5425 points

Hi John,

Below is a link to a E2E FAQ thread on solving link-up issues for the DP83822. Try going through it and see if one of the options can solve your issue.

https://e2e.ti.com/support/interface-group/interface/f/interface-forum/983097/faq-dp83822i-how-to-solve-common-ethernet-phy-link-up-issues?

If you are still having issues after going through the thread, can you provide a register dump of registers 0x00 to 0x1F, 0x0467, and 0x0468 when you are trying to establish the 10/100M link?

Regards,

Adrian Kam

Interface

Interface forum

DP83822IF: Cannot link with gigabit Ethernet port of PC