W79E825A Datasheet, PDF (94/127 Pages) Winbond – 8-BIT MICROCONTROLLER

W79E825A/824A/823B/822B Data Sheet
21 OSCILLATOR
The W79E825 series provides three oscillator input option. These are configured at CONFIG register
(CONFIG1) that include On-Chip RC Oscillator Option, External Clock Input Option and Crystal
Oscillator Input Option. The Crystal Oscillator Input frequency may be supported from 4MHz to
20MHz, and without capacitor or resistor.
Figure 21-1: Oscillator
21.1 On-Chip RC Oscillator Option
The On-Chip RC Oscillator is fixed at 6MHz +/- 25% frequency to support clock source. When FOSC1,
FOSC0 = 01b, the On-Chip RC Oscillator is enabled. A clock output on P2.0 (XTAL2) may be enabled
when On-Chip RC oscillator is used.
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