MC68HC12 Datasheet, PDF (157/478 Pages) Motorola, Inc – The MC68HC912DT128A microcontroller unit (MCU) is a 16-bit device composed of standard on-chip peripherals including a 16-bit central processing unit

Technical Data — MC68HC912DT128A
Section 12. Clock Functions
12.1 Contents
12.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157
12.3 Clock Sources. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158
12.4 Phase-Locked Loop (PLL) . . . . . . . . . . . . . . . . . . . . . . . . . . . 159
12.5 Acquisition and Tracking Modes. . . . . . . . . . . . . . . . . . . . . . .161
12.6 Limp-Home and Fast STOP Recovery modes . . . . . . . . . . . . 163
12.7 System Clock Frequency Formulae . . . . . . . . . . . . . . . . . . . . 181
12.8 Clock Divider Chains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .182
12.9 Computer Operating Properly (COP) . . . . . . . . . . . . . . . . . . .185
12.10 Real-Time Interrupt. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
12.11 Clock Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186
12.12 Clock Function Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
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 MC68HC912DT128A.
MC68HC912DT128A — Rev 4.0
MOTOROLA
Clock Functions
Technical Data
157