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DS110DF410 - RAW output, CDR

Kawai
Guru 19785 points
Other Parts Discussed in Thread: DS110DF410

Hi,

I have questions about RAW output mode.

[Question]
When you set the DS110DF410 OUTPUT MUX to RAW output, which point of the data would be the output ?
Is it the data after CTLE or DFE ?

[Question]
When set in RAW output mode, is the input data after equalization still go into CDR block, or is it switched off ?
I wanted to know if the LOCK pin function and HEO/VEO function is available in RAW output mode.

Best Regards,
Kawai

  • 0
    TI__Guru* 93670 points

    Kawai-San,

    When we are in raw mode, the output data would be after the CTLE and DFE and before the CDR.

    So even when we are in raw mode the data is still going into the CDR block.

    Regards,,nasser

  • 0
    TI__Intellectual 1985 points

    Hello Kawai,

    The RAW mode signal is after the CTLE and after the DFE. The CDR can still lock and the CTLE/DFE can still adapt even if the output mux is set to RAW. In fact, if the channel is locked, not only will you be able to read out valid HEO and VEO values, but the RAW signal you observe will have CTLE and DFE equalization applied. 

    If you want to use RAW mode when the CDR is unlocked, then you will need to do some extra steps for a meaningful RAW eye measurement:

    1. Put the channel into adapt mode 0 in order to prevent the CTLE from cycling through different values while the channel is attempting to acquire lock: Write 2'b00 to channel register 0x31[6:5].
    2. Put the device into reference mode 0 in order to prevent the state machine from controlling the analog circuits while the channel is attempting to acquire lock: Write 2'b00 to channel register 0x36[5:4].
    3. Disable the DFE, since it will not be performing a meaningful function unless the CDR is locked: Write 1'b1 to channel register 0x1E[3].
    Regards,
    Casey
  • 0 in reply to Casey Morrison
    Guru 19785 points

    Casey-san,

    Thank you very much for the answer.

    Best Regards,
    Kawai