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RFPIC12F675K Datasheet, PDF (57/136 Pages) Microchip Technology – 20-Pin FLASH-Based 8-Bit CMOS Microcontroller with UHF ASK/FSK Transmitter | |||
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10.0 SPECIAL FEATURES OF THE
CPU
Certain special circuits that deal with the needs of real
time applications are what sets a microcontroller apart
from other processors. The rfPIC12F675 Family has a
host of such features intended to:
⢠maximize system reliability
⢠minimize cost through elimination of external
components
⢠provide power saving operating modes and offer
code protection.
These features are:
⢠Oscillator selection
⢠RESET
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Detect (BOD)
⢠Interrupts
⢠Watchdog Timer (WDT)
⢠SLEEP
⢠Code protection
⢠ID Locations
⢠In-Circuit Serial Programming
rfPIC12F675
The rfPIC12F675 has a Watchdog Timer that is
controlled by configuration bits. It runs off its own RC
oscillator for added reliability. 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 (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 provide at least
a 72 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 10-1).
 2003 Microchip Technology Inc.
Preliminary
DS70091A-page 55
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