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Original question:

DS90UB948-Q1: DESER 948 LOCK Pin Issue

DS90UB948-Q1: display abnormal reason analyse

HB ZHANG
Prodigy 50 points

Part Number: DS90UB948-Q1
Other Parts Discussed in Thread: ALP

Hello , TI team

           We use 948 Der to design Car's IVI display product, and to match  mainmachine's  947 Ser.  Some times, we have received some complaint from customer, because they found the screen display abnormal , such as flicker, black screen, frame skip display, etc.  Except to some reason from MCU in that system, I more want to know how to analyse Des's or Ser's itsself issue. such as 948's LOCK pin always LOW will result into no display in screen. could you provide guigeline or related genernal documents  to help us to locate problemlocation  in quickly.

          thank you in advance!

  • 0
    TI__Mastermind 38895 points

    Hi HB,

    If the 948 lock pin is low, the 948 will not be able to recover the serial stream sent by the serializer. This is why you are seeing no display when 948 lock pin is low. TI has a program called Margin Analysis Program (MAP) that allows for diagnosing link issues. This is included in the ALP profile for the 948.

    The app note for the MAP program: Link

    Have you reached out to your local FAE representative? They can help if you are not familiar with ALP.

    Best,

    Jack

  • 0 in reply to Jack Scherlag
    Prodigy 50 points

    Hello， Jack

          This is just an example about LOCK pin. actually, we want to acquired Fault tree analysis or similar guideline to help us fonud 948's problem more quickly. 

          I know that MAP software， but I remeber MAP used to analysis the link is ok or bad, how much margin.  And you meaning we can found some registers para in MAP , to indicate to somewhere has issue ?

  • +1 in reply to HB ZHANG
    TI__Mastermind 38895 points

    Hi HB,

    I recommend starting with MAP software as the quality of the link itself is very important. This causes most of the screen flickering issues for these devices. There is also a built-in self test (BIST) feature on the 948 to check for errors received over the link. The BIST procedure is outlined in the 948 datasheet section 7.3.15

    Best,

    Jack

  • 0 in reply to Jack Scherlag
    Prodigy 50 points

    Hello，Jack

    Thank you for your suggestion, I  got it.