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TLK2501: IDLE character

Part Number: TLK2501

Why does this device allow either D5.6 or D16.2 to complete the IDLE character?

Would the device care if I just picked one of them and called it good?  

I understand that D5.6 does not have disparity, whereas D16.2 does. 

As an example, I could use K28.5 to control my disparity, and use D5.6, since it would not adjust disparity.

Or, I could use D16.2, and both K28.5 and D16.2 would adjust the disparity...

Would the IC be upset if I only set D16.2 or D5.6 after the K28.5?

  • Hi Dan,

    We have assigned your question to apps team and will provide an update soon.

    Dennis
  • Hello Dan,

    Sorry for the delayed response. Basically, the encoder of the device inserts IDLE character when no payload data is available to send (K28.5, D5.6 or K28.5, D16.2).
    According to the state machine of this device, this one accepts 3 consecutive valid IDLEs or carrier extends or even 1 valid data/error propagation to establish the link and sync the device (valid code word received).
    The device needs a K28.5 (BC) code followed by either D5.6 (C5) or D16.2(50) code.

    Regards,
    Luis Omar Moran
    High Speed Interface
    SWAT Team
  • Can I just pick D5.6 or D16.2 to use as an idle?  Or does the IC need me to alternate between these two characters (or use some other algorithm).  This assumes that I always send the K28.5.

    What do you mean by 3 consecutive valid IDLEs?  Should I be guaranteeing that I send 3 IDLEs in a row?

  • Hi Dan,

    You could use either D5.6(C5) or D16.2(50) after of K28.5 (BC). The device needs to detect 3 consecutive valid IDLEs to sync the device.

    Regards,
    Luis
  • Is there a method for when to select the D5.6 versus the D16.2?  Or can I just choose them randomly?

    Can I just pick one an run with it, or do I need to somehow alternate between the two?

  • Hi Dan,

    You can just select one of them or alternate them, is up to the user. Basically the state machine of the device, upon power up/reset enters in the acquisition status and searches for 3 IDLEs to sync the device.

    Regards,
    Luis Omar Moran
    High Speed Interface
    SWAT Team