MFR4300 Datasheet, PDF (233/266 Pages) Freescale Semiconductor, Inc – FlexRay Communication Controllers

Chapter 7
Oscillator (OSCV2)
7.1 Introduction
The OSCV2 module provides one oscillator concept:
• A robust full swing Pierce oscillator with the possibility to feed in an external square wave
7.1.1 Features
The Pierce oscillator provides the following features:
• Wide 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
Common features:
• Clock monitor (CM)
• Operation from the V_DDOSC 2.5 V (nominal) supply rail
7.1.2 Modes of Operation
One mode of operation exists:
• 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
7.2 External Signal Description
This section lists and describes the signals that connect off chip.
7.2.1 V_DDOSC and V_SSOSC — OSC Operating Voltage, OSC Ground
These pins provide the operating voltage (V_DDOSC) and ground (V_SSOSC) for the OSCV2 circuitry. This
allows the supply voltage to the OSCV2 to be independently bypassed.
7.2.2 EXTAL and XTAL — Clock/Crystal Source Pins
These pins provide the interface for either a crystal or a CMOS compatible clock to control the internal
clock generator circuitry. EXTAL is the external clock input or the input to the crystal oscillator amplifier.
MFR4300 Data Sheet, Rev. 1
Freescale Semiconductor
233