DP83TG720EVM-MC: DP83TG720 setup on via just strapping resistors

kenneth nguyen

Part Number: DP83TG720EVM-MC

Hi I currently have a custom design on an FPGA board that uses the DP83TG720RWRHATQ1. The strapping resistors on the custom PCB have the DP83TG720RWRHATQ1 set to RGMII, autonomous and slave mode with RX and TX shift mode.

I am currently trying to connect the custom board to the DP83TG720EVM-MC that then connects to the computer to ping the FPGA and test our automotive ethernet design. After I connect the hardware and attempt to ping the static IP address on my FPGA through my PC - I am unable to reach it. I also notice that the link LED and activity LED do not blink and are off on the eval board.

Is there any further setup needed through MDIO to setup the DP83TG720RWRHATQ1 or are the strapping resistors enough? Thank you for any feedback and guidance in advance.

over 2 years ago

0 Hillman Lin over 2 years ago

TI__Mastermind 25955 points

Hi Kenneth,

An register read would be useful to debug the DP83TG720 PHY.

I am not sure if I understand your question completely, Are you not able to perform a link or ping DP83TG720EVM with the PC? If so, are you able to read register on the PC?

Some test we can do without the registers for debug:

Check VDDA and VDDIO voltage
Check Rbias resistance value and voltage
Check reset pin rather to make sure it is not active low

Regards,

Hillman Lin

0 kenneth nguyen over 2 years ago in reply to Hillman Lin

Prodigy 60 points

Hi, Hillman

I am having issues bringing up the custom DP83TG720 PHY design. I was reading through this thread https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1213654/dp83tg720s-q1-u-boot-cannot-initiate
One thing i would like to understand is that can the DP83TG720 be initiated without the software? if you do not understand this question can you refer me to a firmware engineer who does?

0 Hillman Lin over 2 years ago in reply to kenneth nguyen

TI__Mastermind 25955 points

HI Kenneth,

DP83TG720 could be configure using only strap option without software configuration.

However, there is limited option we can debug with only strap option without accessing register.

Some test we can do without the register for debug:

Check VDDA and VDDIO voltage
Check Rbias resistance value and voltage
Check reset pin rather to make sure it is not active lo

Regards,

Hillman Lin

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DP83TG720EVM-MC: DP83TG720 setup on via just strapping resistors