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DS90CR486: No Output

user5163865
Genius 3525 points
Part Number: DS90CR486
Other Parts Discussed in Thread: DS90CR485,

Hi,

The customer has connected and tested the "transmitter DS90CR485" and "receiver DS90CR486", but the receiver DS90CR486 does not output data.

They have confirmed below.
・ RxCLKOUT (125MHz) of the receiver is output.
・ RxOUTxx of the receiver remains 0 for all bits
・ Confirmed up to RxINPx / RxINMx of the receiver

I think that the configuration is not done correctly because it is input but not output.

So, is there a timing chart for the configuration sequence on the sending side and receiving side?

If you have any other possible causes, we would appreciate it if you could let us know.

The configuration used is Configuraion 5 (DS90CR486 ’s BAL = High, CON1 = High, 125MHz).

Best regards,
Hiroshi

  • 0
    TI__Mastermind 25735 points

    Hi Hiroshi,

    Can you confirm the Receiver is properly powered by probing the power and control pins of the device? Also, it would be good to make sure PD is not being held low. If PD is low, the outputs of the device will also be low.

    user5163865 said:
    So, is there a timing chart for the configuration sequence on the sending side and receiving side?

    I'm not exactly sure what you are referring to here, but both datasheets have a AC Timing Diagrams section which may have what you are looking for.

    Regards,

    Ben

  • 0 in reply to Ben Dattilo
    Genius 3525 points

    Hi Ben,
    Thanks,

    I found the "transmitter DS90CR485" and "receiver DS90CR486" EVMs. There seems to be useful information in UG, so I sent it to the customer.
    Customers are now checking the operation while watching UG. I will report when it is resolved.

    Best regards,
    Hiroshi

  • 0 in reply to user5163865
    TI__Mastermind 25735 points

    Hi Hiroshi,

    Thank you. Please feel free to post here with any updates or additional questions.

    Regards,

    Ben

  • 0 in reply to Ben Dattilo
    Genius 3525 points

    Hi

    User system doesn't seem to work yet.
    As far as I can see the DS, the configuration of this device looks like the following except PD.

    CR485 (TX): When the power is turned on, the DS_OPT pin can be either HI or Low.
    　　　　　　Clock input "20ms + 4096 clock input" is required for the receiver to complete the "Deskew operation".

    CR486 (RX): "DESKEW" pin and CON1 pin are High

    Is there anything else we need to do?
    Our customer requested a timing chart, but I don't think there is any timing to consider as you say. is it correct?

    Best regards,

    Hiroshi

  • 0 in reply to user5163865
    TI__Mastermind 25735 points

    Hi Hiroshi,

    Can you confirm the PD pin of the CR486 is tied to an input level of 2.5V to Vcc, and that his pin is not de-asserted?

    By timing chart, do you mean power-up timing for the two devices? I believe the only timing charts we have for these devices are what is in the respective datasheets. However, in general it is usually the case that the deserializer should be powered up after the serializer.

    Regards,

    Ben

  • 0 in reply to Ben Dattilo
    Genius 3525 points

    Hi Ben-san,

    The sequence that the customer says refers to the following PIN setting order in the explanation of Config 5.

    ”BAL = Hiigh, CON1 = High, DS_OPT pin at the input of the transmitter DS90CR485 can be set to High OR Low when power up”

    First, request a power sequence.
    It's too simple a problem, so we will check for a device failure.

    Best regards,

    Hiroshi

  • 0 in reply to user5163865
    TI__Mastermind 25735 points

    Hi Hiroshi,

    Okay, let me know any additional results. To my knowledge we do not have a power sequence diagram for these devices. I would also reiterate my previous suggestion in testing the PD pin.

    Regards,

    Ben

  • 0 in reply to Ben Dattilo
    Genius 3525 points

    Ben,

    Upon closer inspection, the DESKEW pin was unintentionally a Low input.
    I apologize for confusing you.

    The problem has been resolved.

    Thank you.

    Best regards,
    Hiroshi