Hi all ! On another thread (cheat sheet thread), I have explain I use launchpad for driving a SI570.
some of you have need I share my work. it's ok... ;-) look attachment file.
For understand my work, i preconise to read the datasheet.
The SI570 have 2 mode for change frequency, i use the "long" mode. I recalc all parameters in every change frequency.
But i simplify the calcul by the systematic use of initial frequency in place of read all registers for determinize actual ferquency to recalc new freq. (I think attiny/softrock already uses this trick.)
but, I have 2 problems (in Fxtal