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DS250DF230: Standard Rate Modes Configurable from Reg_0x2F

K.Yaita
Guru 29720 points
Part Number: DS250DF230
Other Parts Discussed in Thread: DS250DF410, DS280DF810,

Hi Team,

Programmer's Guide shows "Standard Rate Modes Configurable from Reg_0x2F" in Table 24 (page 22).
However the table is valid only when the calibration clock is 30.72MHz.

Is there same table for calibration clock is 25MHz?

Best Regards,
Yaita

  • 0
    TI__Guru* 93670 points

    Hi Yaita,

    You can refer to other 28G(DS280DF810) or 25G(DS250DF410) retimers where 25MHz reference clock is used.

    Regards,, Nasser

  • 0 in reply to Nasser Mohammadi
    Guru 29720 points

    Hi Nasser-san,

    Did you refer Table 23 in Programmer's Guide can be applied to DS250DF230 when calibration clock is 25MHz?
    I believe DS250DF230 prepared Table 24 that can be applied only when calibration clock is 30.72MHz, and if my customer wants to use 25MHz calibration clock he should use "Manual Data Rate Configuration".

    Which is correct?

    Best Regards,
    Yaita

  • 0 in reply to K.Yaita
    TI__Guru* 93670 points

    Hi Yaita-San,

    Your understanding is correct. For 25MHz reference clock we should use manual settings. Please refer to the DS250DF230 programming guide section 7.7.1.

    Regards,, Nasser

  • 0 in reply to Nasser Mohammadi
    Guru 29720 points

    Hi Nasser-san,

    Thank you for your reply.

    I understand however Table 25 in section 7.7.1 in programming guide shows the following.
    >(1) These rates can also be configured by selecting the appropriate rate setting in Reg_0x2F.

    I believe it is typo because for 25MHz calibration clock, we should use manual settings only.
    Is my understanding correct?

    Best Regards,
    Yaita

  • 0 in reply to K.Yaita
    TI__Mastermind 19235 points

    Standard rates are also available for DS250DF230 but they vary depending on calibration clock frequency. To minimize confusion I recommend to use manual CDR rate configuration based on the correct calibration clock frequency.

    Regards,

    Rodrigo