• State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 33 subscribers
  • Views 376 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.

DS90UB913Q/914Q test documents for transmitted signal quality measurement...

Peter Tseng
Mastermind 6170 points

Dear Sirs,

Does anyone have idea how to measure the signal quality that transmitted by DS90UB913Q and DS90UB914Q?

For example, we can determine the USB signal which one is OK and which one is bad by the equipment and eye diagram.

However, even 931Q and 914Q signal are differential signals, there is no standard specification to judge the signal quality is good enough or not.

Please help to give me some ideas about it!

Very appreciate! 

  • 0
    TI__Genius 13475 points
    Because there are two channels superimposed, it is very difficult to evaluate the signal integrity of the FPD link by looking at the FPD link itself. You can isolate the forward or backchannels - to see just the forward channel as is is received by the deserializer, enable the CMLOUT pins, and attach the CMLOUT pins to a high speed scope, you should be able to see an eye diagram there. To isolate the backchannel, you can do a similar thing, sending the recovered backchannel signal to the GPIO0 pin, where it can be observed. The best way to verify the integrity of the link is to use the Built In Self Test - BIST, as described in the datasheet.