PIC16F684
12.0
SPECIAL FEATURES OF THE
CPU
The PIC16F684 has two timers that offer necessary
delays on power-up. One is the Oscillator Start-up
Timer (OST), intended to keep the chip in Reset until
the crystal oscillator is stable. The other is the Power-up
Timer (PWRT), which provides a fixed delay of 64 ms
(nominal) on power-up only, designed to keep the part
in Reset while the power supply stabilizes. There is also
circuitry to reset the device if a brown-out occurs, which
can use the Power-up Timer to provide at least a 64 ms
Reset. With these three functions-on-chip, most
applications need no external Reset circuitry.
The Sleep mode is designed to offer a very low -current
Power-down mode. The user can wake-up from Sleep
through:
• External Reset
• Watchdog Timer Wake-up
• An interrupt
Several oscillator options are also made available to
allow the part to fit the application. The INTOSC option
saves system cost while the LP crystal option saves
power. A set of configuration bits are used to select
various options (see Register 12-1).
The PIC16F684 has a host of features intended to
maximize system reliability, minimize cost through
elimination of external components, provide power
saving features and offer code protection.
These features are:
• Reset
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Detect (BOD)
• Interrupts
• Watchdog Timer (WDT)
• Oscillator selection
• Sleep
• Code protection
• ID Locations
• In-Circuit Serial Programming
2004 Microchip Technology Inc.
Preliminary
DS41202C-page 91
MICROCHIP [ MICROCHIP TECHNOLOGY ]
