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DS110DF410: How often and when are these parameters updated?

Part Number: DS110DF410
Other Parts Discussed in Thread: DS110DF1610

Hi,

Our customer is confirming the EOM of TI Retimers, DS110DF1111, DS110DF401 and DS110DF1610. Then, would you give me some information regarding the following? How often and when are these parameters updated?

1)the value of CTLE -> Is the data updated periodically in CTLE Adapt mode?

2)the value of HEO(0x27)/VEO(0x28) -> I think 2) is updated  in conjunction with 1).

3)When is the incoming data updated for EOM(0x25,0x26)?

Best Regards,

Toshiyuki

 

  • Hello Toshiyuki-san,

    Thank you for using the TI forum. Our product expert will get back to you by Wednesday.
  • Hi Toshiyuki, see below.

    1)the value of CTLE -> Is the data updated periodically in CTLE Adapt mode?

    • The CTLE boost value is not updated periodically. The retimer performs an automatic Rx EQ adaption upon first detecting input data. Once that initial adaption is complete the retimer maintains the CTLE setting determined during the auto adaption

    2)the value of HEO(0x27)/VEO(0x28) -> I think 2) is updated  in conjunction with 1).

    • The HEO and VEO values update rate is in the order of micro-seconds. The retimer uses the internally measured HEO and VEO values as part of the Rx EQ adaption, not the other way around

    3) When is the incoming data updated for EOM(0x25,0x26)?

    • These registers are only used when the host is implementing a full EOM eye contour operation. See below

    Plotting an Eye Diagram

    The Eye Opening Monitor is capable of plotting an equalized, but non-retimed eye to represent the quality of signal that is going into the CDR block. This feature is useful for diagnosing gross signal integrity errors. The eye plot generated by the EOM cannot be used to extrapolate performance to bit error rates beyond 1e-7.

    The EOM generates the eye plot according to a 64 x 64 matrix. Each grid space in the matrix consists of a 16-bit word that represents the number of times the incoming data stream touches that particular phase and voltage level. The EOM under-samples the incoming data stream by recording the total hit count for each combination of phase and voltage, one grid space at a time.

    To configure the EOM to plot the eye diagram, sometimes called fast eye capture, use the following registers.

    Step

    Register[bits]

    Value

    Description

    1

    0x3E[7]

    0

    Disable lock EOM lock monitoring

    2

    0x2C[6]

    0x11[7:6]

    0

    2’b xx

    Set the desired EOM vertical range as 2’b xx

    3

    0x11[5]

    0

    Power on the EOM

    4

    0x24[7]

    1

    Enable fast EOM

    5

    0x24[0]

    0x25

    0x26

    1

    When 24[0]   is 1 begin read out of the 64 x 64 array, discard first 4 bytes
    This bit is self-clearing.

    6

    0x24[0]

    0x25

    0x26

    1

    Continue reading information until the 64 x 64 array is complete.

    7

    0x3E[7]

    0x2C[6]

    0x11[5]

    0x24[7]

    1

    1

    1

    0

    Return the EOM to its original state. Undo steps 1-4

     

     

    The data recorded from the Eye Opening Monitor (EOM) begins at (X, Y) position (0, 0) and proceeds to position (0, 63). Next, the Y-value is reset to 0 and the X-value is incremented. This process is repeated until the entire 64 x 64 matrix is read out

     

    Regards,

    Rodrigo Natal

    HSCC Applications Engineer

  • Hi Rodrigo-san,

    Thank you for the reply. I'd like to understand in more detail. When 24[0] is changed 0 to 1, is the incoming data accumulated for EOM?  Or is the accumulated data updated periodically?

    Best Regards,

    Toshiyuki

  • The accumulated data is updated periodically.