PIC18F23K20_10 Datasheet, PDF (299/456 Pages) Microchip Technology – 28/40/44-Pin Flash Microcontrollers with nanoWatt XLP Technology

23.0 SPECIAL FEATURES OF
THE CPU
PIC18F2XK20/4XK20 devices include several features
intended to maximize reliability and minimize cost through
elimination of external components. These are:
• Oscillator Selection
• Resets:
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
• Interrupts
• Watchdog Timer (WDT)
• Code Protection
• ID Locations
• In-Circuit Serial Programming™
The oscillator can be configured for the application
depending on frequency, power, accuracy and cost. All
of the options are discussed in detail in Section 2.0
“Oscillator Module (With Fail-Safe Clock Monitor)”.
A complete discussion of device Resets and interrupts
is available in previous sections of this data sheet.
In addition to their Power-up and Oscillator Start-up
Timers provided for Resets, PIC18F2XK20/4XK20
devices have a Watchdog Timer, which is either
permanently enabled via the Configuration bits or
software controlled (if configured as disabled).
The inclusion of an internal RC oscillator also provides
the additional benefits of a Fail-Safe Clock Monitor
(FSCM) and Two-Speed Start-up. FSCM provides for
background monitoring of the peripheral clock and
automatic switchover in the event of its failure. Two-
Speed Start-up enables code to be executed almost
immediately on start-up, while the primary clock source
completes its start-up delays.
All of these features are enabled and configured by
setting the appropriate Configuration register bits.
PIC18F2XK20/4XK20
 2010 Microchip Technology Inc.
DS41303G-page 299