PIC16F628-20P Datasheet, PDF (93/170 Pages) Microchip Technology – FLASH-Based 8-Bit CMOS Microcontroller

14.0 SPECIAL FEATURES OF THE
CPU
Special circuits to deal with the needs of real-time
applications are what sets a microcontroller apart from
other processors. The PIC16F62X 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 are:
1. OSC selection
2. RESET
3. Power-on Reset (POR)
4. Power-up Timer (PWRT)
5. Oscillator Start-Up Timer (OST)
6. Brown-out Reset (BOD)
7. Interrupts
8. Watchdog Timer (WDT)
9. SLEEP
10. Code protection
11. ID Locations
12. In-circuit Serial Programming
The PIC16F62X has a Watchdog Timer which 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 provides 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 or through an interrupt. Several oscillator
options are also made available to allow the part to fit
the application. The ER oscillator option saves system
cost while the LP crystal option saves power. A set of
configuration bits are used to select various options.
PIC16F62X
14.1 Configuration Bits
The configuration bits can be programmed (read as '0')
or left unprogrammed (read as '1') to select various
device configurations. These bits are mapped in
program memory location 2007h.
The user will note that address 2007h is beyond
the user program memory space. In fact, it belongs
to the special configuration memory space (2000h –
3FFFh), which can be accessed only during
programming. See Programming Specification.
 2003 Microchip Technology Inc.
Preliminary
DS40300C-page 91