SNAS750B November 2020 – March 2021 LMK5C33216
PRODUCTION DATA
To adjust APLL DCO, DPLLx_FREE_RUN field is written to. When DPLLx_HIST_EN = 1, the relative adjustements are performed. When DPLLx_HIST_EN = 0 the DPLLx_FREE_RUN value is used for the APLLx DCO numerator. The effective APLLx numerator can be read back from APLLx_NUM_STAT.
Equation 12 shows the formula to compute the DPLLx_FREE_RUN field value required to meet the specified DCO frequency step size in ppb (part-per-billion) when relative APLL DCO mode is enabled. DPLLx_FREE_RUN is a signed value and the actual programmed value for a negative number can be calculated as the 2s complement.
where