Chapter 27
Multipurpose Clock Generator Lite (MCG_Lite)
27.1 Introduction
The Multipurpose Clock Generator Lite (MCG_Lite) module provides several clock
source options for the MCU. This module contains one 48 MHz and one 8/2 MHz
Internal Reference Clock (IRC) sources. The module selects one of IRCs or External
Oscillator/Clock (EXT) as the MCU clock sources. It also provides USB recovery
interface for the 48 MHz IRC.
27.1.1 Features
The MCG_Lite module has the following features:
• High-frequency Internal Reference Clock (HIRC)
• 48 MHz clock source
• Support various trims to achieve target accuracy
• Support USB recovery feature
• Low-frequency Internal Reference Clock (LIRC)
• Selectable 8 MHz or 2 MHz clock source
• Trim bit to ensure ±3% accuracy across PVT
• Glitchless clock switcher for internal clock sources (HIRC and LIRC) and external
clock source (EXT)
• Dedicated high frequency clock sources output (MCGPCLK) for peripheral use
• Dedicated low frequency clock sources output (LIRC_CLK) for peripheral use
• Divider/prescaler (FCRDIV) for low frequency IRC to support /1, /2, /4, /8, /16, /
32, /64, and /128 division factors
• Second divider (LIRC_DIV2) to support /1, /2, /4, /8, /16, /32, /64, and /128 division
factors
• Control signal for the external clock/oscillator (EXT)
• EREFS0, HGO0, RANGE0
• External clock from crystal oscillator can be used as system clock sources
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
Freescale Semiconductor, Inc.
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