MC9S08GB60 Datasheet, PDF (10/290 Pages) Motorola, Inc – Microcontrollers

Section Number
Title
Page
Chapter 7
Internal Clock Generator (ICG) Module
7.1 Introduction .....................................................................................................................................99
7.1.1 Features ..........................................................................................................................100
7.1.2 Modes of Operation .......................................................................................................101
7.2 External Signal Description ..........................................................................................................101
7.2.1 Overview ........................................................................................................................101
7.2.2 Detailed Signal Descriptions .........................................................................................102
7.2.2.1 EXTAL— External Reference Clock / Oscillator Input ...............................102
7.2.2.2 XTAL— Oscillator Output ...........................................................................102
7.2.3 External Clock Connections ..........................................................................................102
7.2.4 External Crystal/Resonator Connections .......................................................................102
7.3 Functional Description ..................................................................................................................103
7.3.1 Off Mode (Off) ..............................................................................................................103
7.3.1.1 BDM Active .................................................................................................103
7.3.1.2 OSCSTEN Bit Set .........................................................................................103
7.3.1.3 Stop/Off Mode Recovery ..............................................................................104
7.3.2 Self-Clocked Mode (SCM) ............................................................................................104
7.3.3 FLL Engaged, Internal Clock (FEI) Mode ....................................................................105
7.3.3.1 FLL Engaged Internal Unlocked ..................................................................105
7.3.3.2 FLL Engaged Internal Locked ......................................................................106
7.3.4 FLL Bypassed, External Clock (FBE) Mode ................................................................106
7.3.5 FLL Engaged, External Clock (FEE) Mode ..................................................................106
7.3.5.1 FLL Engaged External Unlocked .................................................................106
7.3.5.2 FLL Engaged External Locked .....................................................................107
7.3.6 FLL Lock and Loss-of-Lock Detection .........................................................................107
7.3.7 FLL Loss-of-Clock Detection ........................................................................................107
7.3.8 Clock Mode Requirements ............................................................................................108
7.3.9 Fixed Frequency Clock ..................................................................................................109
7.4 Initialization/Application Information ..........................................................................................110
7.4.1 Introduction ....................................................................................................................110
7.4.2 Example #1: External Crystal = 32 kHz, Bus Frequency = 4.19 MHz .........................112
7.4.3 Example #2: External Crystal = 4 MHz, Bus Frequency = 20 MHz ............................113
7.4.4 Example #3: No External Crystal Connection, 5.4 MHz Bus Frequency .....................114
7.4.5 Example #4: Internal Clock Generator Trim .................................................................116
7.5 ICG Registers and Control Bits .....................................................................................................117
7.5.1 ICG Control Register 1 (ICGC1) ......................................................................118
7.5.2 ICG Control Register 2 (ICGC2) ......................................................................119
7.5.3 ICG Status Register 1 (ICGS1) .................................................................................120
7.5.4 ICG Status Register 2 (ICGS2) ........................................................................122
7.5.5 ICG Filter Registers (ICGFLTU, ICGFLTL) .......................................................122
7.5.6 ICG Trim Register (ICGTRM) ...........................................................................123
MC9S08GB/GT Data Sheet, Rev. 2.3
10
Freescale Semiconductor