z8f083a ZiLOG Semiconductor, z8f083a Datasheet - Page 157

• Manufacturer Part Number: z8f083a
• Description: High-performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

Oscillator Control
Operation
PS026308-1207
System Clock Selection
The Z8 Encore! F083A Series device uses five possible clocking schemes. Each one of
these is user-selectable.
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In addition, Z8 Encore! F083A Series devices contain clock failure detection and recovery
circuitry, allowing continued operation despite a failure of the primary oscillator.
This chapter discusses the logic used to select the system clock and handle primary
oscillator failures. A description of the specific operation of each oscillator is outlined
elsewhere in this document. The detailed description of the <Cross_Ref>Watchdog Timer
Oscillator starts on page 87, the internal precision oscillator description begins on page
155, and the chapter outlining the crystal oscillator begins on page 151 of this document.
The oscillator control block selects from the available clocks.
describes each clock source and its usage.
On-chip precision trimmed RC oscillator.
On-chip oscillator using off-chip crystal or resonator.
On-chip oscillator using external RC network.
External clock drive.
On-chip low precision Watchdog Timer Oscillator.
Z8 Encore!
Table 94
Product Specification
on page 146
®
F083A Series
Oscillator Control
145