PIC16F87/88
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, or through an interrupt.
15.0 SPECIAL FEATURES OF THE
CPU
These devices have a host of features intended to max-
imize system reliability, minimize cost through elimina-
tion of external components, provide power saving
operating modes and offer code protection:
Additional information on special features is available
in the PICmicro® Mid-Range Reference Manual
(DS33023).
• RESET
15.1 Configuration Bits
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
• Interrupts
The configuration bits can be programmed (read as
‘0’), or left unprogrammed (read as ‘1’), to select vari-
ous device configurations. These bits are mapped in
program memory locations 2007h and 2008h.
• Watchdog Timer (WDT)
• Two-Speed Start-up
• Fail-Safe Clock Monitor
• SLEEP
The user will note that address 2007h is beyond the
user program memory space, which can be accessed
only during programming.
• Code Protection
• ID Locations
• In-Circuit Serial Programming™ (ICSP™)
There are 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 72 ms (nomi-
nal) on power-up only. It is designed to keep the part in
RESET while the power supply stabilizes, and is
enabled or disabled using a configuration bit. With
these two timers on-chip, most applications need no
external RESET circuitry.
2003 Microchip Technology Inc.
Preliminary
DS30487B-page 129
MICROCHIP [ MICROCHIP ]
