• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 34 subscribers
  • Views 394 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.

Original question:

DS32EV400: Why the DS32EV400 has not detect failure at SD_Output?

DS32EV400: DS32EV400: Why the DS32EV400 has not detect failure at SD_Output?

Manuel Infante
Intellectual 1300 points
Part Number: DS32EV400


The DS32EV400- is used on a COM-Express-Carrier-Design.
 The Displayport-Output of as COM-Express-Module is with the Inputpins IN_0 +/- to IN_3 +/- from DS32EV400 connected.

The lane status is controlled by the outputs SD [0..3] . This works fine.

Now I had a failure, the connection to IN_2 was interrupt. But the SD[2]- Output was still high.
 Why the DS32 has not detect this failure at SD_Output?

To turn SD off the input voltage should be less than 40mV.  Is there crosstalk on the input which exceeds this level?

There is crosstalk on the input, but it is in phase with with the signal on SD[2]+.

Is there way to detect something is wrong, because this signal should be the complement?

 

  • 0
    TI__Guru* 93670 points
    Hi Manuel,
    1). You said the signal was interrupted. Does it mean IN-2 signal was on, then it turned off, and finally it came back on again ? During these transitions SD[2] was always on? Is this what you mean?
    2). Or you mean signal was on and then off. Meanwhile SD[2] is asserted even though incoming signal is not present?
    Which one is correct?
    3). It seems this is occurring on IN-2 only. Does this occur on all devices or just one unit? Is this a new design? Please provide more background information.
    Regards,,nasser
  • 0 in reply to Nasser Mohammadi
    TI__Intellectual 1165 points
    Hi Nasser,

    IN-2 had no connection due to solder issue with the BGA but SD2 was still high. All other pins were soldered correctly and the other signals were fine.

    Please help to understand the reason for SD2 to not go low.

    Best regards
    Cevin
  • 0 in reply to Cevin
    TI__Guru* 93670 points
    Hi Cevin,
    It is possible that since IN2 has no connection and it is floating noise due to the power supply or cross coupling could be causing IN2 to chatter and therefor you would see SD2 active.
    1). If you put scope on SD2, is it active all the times or it becomes de-asserted once in a while?
    2). Is it possible to externally terminate IN2 signal to ground?
    Regards,,nasser