Freescale Semiconductor, Inc.
Advance Information — 68HC(9)12D60
Section 12. Clock Functions
12.1 Contents
12.2 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .143
12.3 Clock Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144
12.4 Phase-Locked Loop (PLL) . . . . . . . . . . . . . . . . . . . . . . . . . . .145
12.5 Acquisition and Tracking Modes. . . . . . . . . . . . . . . . . . . . . . .147
12.6 Limp-Home and Fast STOP Recovery modes . . . . . . . . . . . .149
12.7 System Clock Frequency formulas. . . . . . . . . . . . . . . . . . . . .167
12.8 Clock Divider Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .168
12.9 Computer Operating Properly (COP) . . . . . . . . . . . . . . . . . . .172
12.10 Real-Time Interrupt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .173
12.11 Clock Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .173
12.12 Clock Function Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . .174
12.2 Introduction
Clock generation circuitry generates the internal and external E-clock
signals as well as internal clock signals used by the CPU and on-chip
peripherals. A clock monitor circuit, a computer operating properly
(COP) watchdog circuit, and a periodic interrupt circuit are also
incorporated into the 68HC(9)12D60.
68HC(9)12D60 — Rev 4.0
MOTOROLA
Advance Information
Clock Functions
143
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