Z8F042AHJ020SG Datasheet, PDF (210/282 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F082A Series
Product Specification
193
Oscillator Control
The Z8 Encore! XP F082A Series devices uses five possible clocking schemes, each user-
selectable:
• Internal precision trimmed RC oscillator (IPO)
• On-chip oscillator using off-chip crystal or resonator
• On-chip oscillator using external RC network
• External clock drive
• On-chip low power Watchdog Timer oscillator
• Clock failure detection circuitry
In addition, Z8 Encore! XP F082A Series devices contain clock failure detection and
recovery circuitry, allowing continued operation despite a failure of the system clock
oscillator.
Operation
This chapter discusses the logic used to select the system clock and handle primary oscil-
lator failures.
System Clock Selection
The oscillator control block selects from the available clocks. Table 112 details each clock
source and its usage.
PS022827-1212
PRELIMINARY
Oscillator Control