AM62X-PET-CALC: RGM II SRi test fail

Hello Jingcheng

Thank you for the query.

Jingcheng ye said:

In RGMII specification , in my design we can't meet the min SRi  = 2.64ns spec item.

We has tried to modify the ETH phy(88Q1110) into the max driver strength mode, and the test result is 1.8V/ns.

Any suggestion from TI view?

Please share additional details on the signal you are measuring.

Could you please share the waveform and the measurement procedure.

Regards,

Sreenivasa

Hi Sreenivasa

BR Jingcheng

Hello Jingcheng

Thank you.

Kallikuppa Sreenivasa said:

Could you please share the waveform and the measurement procedure.

Pls share the measurement. procedure.

Kallikuppa Sreenivasa said:

Please share additional details on the signal you are measuring.

Please add some information. 

Regards,

Sreenivasa

Hi Sreenivasa

Pls share the measurement. procedure.

--> Jingcheng: Test result is shared , we measured at SOC side of RGMII_RX（0）net.No special setup , but with a ripple cap at probe.

Please add some information. 

---> Jingcheng: i don't under stand what kind of information you want to added?

BR Jingcheng

Jingcheng ye said:

Please add some information. 

---> Jingcheng: i don't under stand what kind of information you want to added?

Please ignore.

 Test result is shared , we measured at SOC side of RGMII_RX（0）net.No special setup , but with a ripple cap at probe.

Does the PHY provide provision to configure internal series resistor or do you have external series resistor or provision to add external series resistor. How long is the trace.

I am not sure if there is anything that can be done on the SoC side.

Regards,

Sreenivasa

Hi Sreenivasa

Yes, you can only focus at checking what can be try on the SOC side.

External part serial resistor and ETH phy driver modification has been try can't meet TI requrirement now.

BR JINGCHENG

Hello Jingcheng

Thank you.

Jingcheng ye said:

Yes, you can only focus at checking what can be try on the SOC side.

Thank you for the suggestions. I am checking internally as i ask additional question to understand the system implementation and setup.

The input i received from the team was to check if the IOs could be operated at 1.8V. 

Jingcheng ye said:

External part serial resistor and ETH phy driver modification has been try can't meet TI requrirement now.

Thanks. 

Sreenivasa

Not meeting the slew requirement erodes timing margins.

Can you switch to 1.8V operation?