Hi Alice,
I did find that reference data sheet and see that the trim is 31.25, but I believe that trim value is from factory.
If you look at the following example from KE02 Sub Family Reference Value:
20.5.1 Initializing FEI mode
The following code segment demonstrates setting ICS to FEI mode.
Example: 20.5.1.1 FEI mode initialization routine
/* the following code segment demonstrates setting ICS to FEI mode generating 36MHz bus*/
ICS_C2 = 0x00; /*BDIV=0, no prescalar
ICS_C1 = 0x04; /* internal reference clock to FLL */
ICS_C3 = TRIM_VALUE_35.15625KHZ; /* FLL output 36MHz */
What is the formula or how do they calculate the 36MHz bus clock?