MC68HC908JB8 Datasheet, PDF (89/286 Pages) Motorola, Inc – MICROCONTROLLERS

Technical Data — MC68HC908JB8•MC68HC08JB8•MC68HC08JT8
Section 7. Oscillator (OSC)
7.1 Contents
7.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
7.3 Oscillator External Connections . . . . . . . . . . . . . . . . . . . . . . . .90
7.4 I/O Signals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
7.4.1 Crystal Amplifier Input Pin (OSC1). . . . . . . . . . . . . . . . . . . . 91
7.4.2 Crystal Amplifier Output Pin (OSC2) . . . . . . . . . . . . . . . . . . 91
7.4.3 Oscillator Enable Signal (SIMOSCEN). . . . . . . . . . . . . . . . . 91
7.4.4 External Clock Source (OSCXCLK) . . . . . . . . . . . . . . . . . . . 91
7.4.5 Oscillator Out (OSCOUT). . . . . . . . . . . . . . . . . . . . . . . . . . . 92
7.5 Low-Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
7.5.1 Wait Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92
7.5.2 Stop Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92
7.6 Oscillator During Break Mode. . . . . . . . . . . . . . . . . . . . . . . . . . 92
7.2 Introduction
The oscillator circuit is designed for use with crystals or ceramic
resonators. The oscillator circuit generates the crystal clock signal. The
crystal oscillator output signal passes through the clock doubler.
OSCXCLK is the output signal of the clock doubler. OSCXCLK is divided
by two before being passed on to the system integration module (SIM)
for bus clock generation.
Figure 7-1 shows the structure of the oscillator. The oscillator requires
various external components.
MC68HC908JB8•MC68HC08JB8•MC68HC08JT8 — Rev. 2.3
Freescale Semiconductor
Oscillator (OSC)
Technical Data
89