mc9s12xf512 Freescale Semiconductor, Inc, mc9s12xf512 Datasheet - Page 193

• Manufacturer Part Number: mc9s12xf512
• Description: S12x Microcontrollers 16-bit Automotive Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Chapter 5
Pierce Oscillator (S12OSCLCPV2)
5.1
The Pierce oscillator (XOSC) module provides a robust, low-noise and low-power clock source. The
module will be operated from the V
of external components. It is designed for optimal start-up margin with typical crystal oscillators.
5.1.1
The XOSC will contain circuitry to dynamically control current gain in the output amplitude. This ensures
a signal with low harmonic distortion, low power and good noise immunity.
5.1.2
Two modes of operation exist:
The oscillator mode selection is described in the Device Overview section, subsection Oscillator
Configuration.
Freescale Semiconductor
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1. Loop controlled Pierce (LCP) oscillator
2. External square wave mode featuring also full swing Pierce (FSP) without internal bias resistor
Revision History
Revision
Number
01.05
02.00
High noise immunity due to input hysteresis
Low RF emissions with peak-to-peak swing limited dynamically
Transconductance (gm) sized for optimum start-up margin for typical oscillators
Dynamic gain control eliminates the need for external current limiting resistor
Integrated resistor eliminates the need for external bias resistor in loop controlled Pierce mode.
Low power consumption:
— Operates from 1.8 V (nominal) supply
— Amplitude control limits power
Clock monitor
Introduction
Features
Modes of Operation
04-Aug-06
Revision
19-Jul-06
Date
Author
MC9S12XF - Family Reference Manual, Rev.1.19
DDPLL
supply rail (1.8 V nominal) and require the minimum number
All xclks info was removed
incremented revision to match the design system spec revision
Description of Changes
193