MCF51CN128 Reference Manual, Rev. 6
Freescale Semiconductor
6-1
Chapter 6
Multipurpose Clock Generator (MCG)
6.1
Introduction
The multipurpose clock generator (MCG) module provides several clock source choices for this device.
The module contains a frequency-locked loop (FLL) and a phase-locked loop (PLL) that are controllable
by either an internal or an external reference clock. The module can select either of the FLL or PLL clocks,
or either of the internal or external reference clocks as a source for the MCU system clock. The selected
clock source is passed through a reduced bus divider which allows a lower output clock frequency to be
derived. The MCG also controls a crystal oscillator (XOSC), which allows an external crystal, ceramic
resonator, or another external clock source to produce the external reference clock.
