Datasheet

interval, two active clock edges are produced. Here, T1 is the previous clock period, and T2 is the period

corresponding to the new prescaler setting.

To avoid unintentional changes of clock frequency, a special write procedure must be followed to change

the CLKPS bits:

1. Write the Clock Prescaler Change Enable (CLKPCE) bit to '1' and all other bits in CLKPR to zero:

CLKPR=0x80.

2. Within four cycles, write the desired value to CLKPS[3:0] while writing a zero to CLKPCE:

CLKPR=0x0N

Interrupts must be disabled when changing prescaler setting to make sure the write procedure is not

interrupted.