Jerry,
I don't know why the code to read out the calibration data from the Si570 is particularly hard. ?These parameters can be read out quite easily but then it does take code to "work backwards" to determine the actual crystal frequency of that particular Si570. ? I consider this a HUGE advantage of using the Si570 instead of the Si5351 in that after the algorithm is developed no calibration to an external source is needed.
-Craig, AA0ZZ
