PIC16F688
The PIC16F688 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.
11.0 SPECIAL FEATURES OF THE
CPU
The PIC16F688 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
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 (WDT)
• Oscillator Selection
• Sleep
• Watchdog Timer Wake-up
• An interrupt
• Code Protection
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 11-1).
• ID Locations
• In-Circuit Serial Programming
2004 Microchip Technology Inc.
Preliminary
DS41203B-page 99
MICROCHIP [ MICROCHIP ]
