• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 33 subscribers
  • Views 404 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

DP83867IR: RGMII timing definition, meaning of 20% to 80%

Oba
Genius 17325 points
Part Number: DP83867IR

Hello,

I have a question or DP83867IR RGMII timing specification.

The datasheet specifies TR(Rise time) and TF (Fall time) as 0.75ns max.
And both rise time and fall time are defined as 20% to 80% like the below.

 

Does this “20% to 80%” mean 20% to 80% of VDDIO? Or 20% to 80% of VIL - VIH? Or other?
Could you please tell me the exact meaning of this 20% to 80%?

 

Regards,
Oba

  • +1
    TI__Expert 5425 points

    Hi Oba-san,

    "20% to 80%" means 20% of RGMII voltage to 80% of RGMII voltage. This RGMII voltage is equal to the VDDIO being used. For example, if VDDIO = 1.8V, then rise time would be the time it takes for the signal to go from 0.36V (20%) to 1.44 V (80%).

    Regards,

    Adrian Kam