MC912DG128A Motorola, MC912DG128A Datasheet - Page 135

• Manufacturer Part Number: MC912DG128A
• Description: Microcontrollers
• Manufacturer: Motorola

1-clock
MOTOROLA
Contents
Introduction
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
Clock Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136
Phase-Locked Loop (PLL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137
Acquisition and Tracking Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139
Limp-Home and Fast STOP Recovery modes . . . . . . . . . . . . . . . . . 141
System Clock Frequency Formulae . . . . . . . . . . . . . . . . . . . . . . . . . 159
Clock Divider Chains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160
Computer Operating Properly (COP) . . . . . . . . . . . . . . . . . . . . . . . . 163
Real-Time Interrupt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Clock Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Clock Function Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165
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.
Clock Functions
Clock Functions
MC68HC912DT128A Rev 2.0
Clock Functions
135