mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 201

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 5
Oscillator (OSCV2)
5.1
The OSCV2 module provides two alternative oscillator concepts:
5.1.1
The Colpitts OSCV2 option provides the following features:
The Pierce OSC option provides the following features:
Common features:
5.1.2
Two modes of operation exist:
Freescale Semiconductor
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A low noise and low power Colpitts oscillator with amplitude limitation control (ALC)
A robust full swing Pierce oscillator with the possibility to feed in an external square wave
Amplitude limitation control (ALC) loop:
— Low power consumption and low current induced RF emission
— Sinusoidal waveform with low RF emission
— Low crystal stress (an external damping resistor is not required)
— Normal and low amplitude mode for further reduction of power and emission
An external biasing resistor is not required
Wider high frequency operation range
No DC voltage applied across the crystal
Full rail-to-rail (2.5 V nominal) swing oscillation with low EM susceptibility
Fast start up
Clock monitor (CM)
Operation from the V
Amplitude limitation controlled Colpitts oscillator mode suitable for power and emission critical
applications
Full swing Pierce oscillator mode that can also be used to feed in an externally generated square
wave suitable for high frequency operation and harsh environments
Introduction
Features
Modes of Operation
DDPLL
2.5 V (nominal) supply rail
MC9S12E256 Data Sheet, Rev. 1.08
201