PIC16C63A Microchip Technology, PIC16C63A Datasheet - Page 81

• Manufacturer Part Number: PIC16C63A
• Description: 28/40-Pin 8-Bit CMOS Microcontrollers
• Manufacturer: Microchip Technology

11.0
The PIC16C63A/65B/73B/74B devices have a host of
features intended to maximize system reliability, mini-
mize cost through elimination of external components,
provide power saving operating modes and offer code
protection. These are:
• OSC Selection
• Reset
• Interrupts
• Watchdog Timer (WDT)
• SLEEP
• Code protection
• ID locations
• In-circuit serial programming
These devices have a Watchdog Timer which can be
shut off only through 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
FIGURE 11-1: CONFIGURATION WORD
1998 Microchip Technology Inc.
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
bit13
bit 13-8
bit 7:
bit 6:
bit 3:
bit 2:
bit 1-0:
Note 1:
CP1
5-4:
SPECIAL FEATURES OF THE
CPU
2:
CP0
CP1:CP0: Code Protection bits
11 = Code protection off
10 = Upper half of program memory code protected
01 = Upper 3/4th of program memory code protected
00 = All memory is code protected
Unimplemented: Read as '1'
BODEN: Brown-out Reset Enable bit
1 = BOR enabled
0 = BOR disabled
PWRTE: Power-up Timer Enable bit
1 = PWRT disabled
0 = PWRT enabled
WDTE: Watchdog Timer Enable bit
1 = WDT enabled
0 = WDT disabled
FOSC1:FOSC0: Oscillator Selection bits
11 = RC oscillator
10 = HS oscillator
01 = XT oscillator
00 = LP oscillator
Enabling Brown-out Reset automatically enables Power-up Timer (PWRT) regardless of the value of bit PWRTE.
Ensure the Power-up Timer is enabled anytime Brown-out Reset is enabled.
All of the CP1:CP0 pairs have to be given the same value to enable the code protection scheme listed.
CP1
CP0
CP1
CP0
—
(2)
BODEN
(1)
(1)
CP1
PIC16C63A/65B/73B/74B
CP0
PWRTE
other is the Power-up Timer (PWRT), which provides a
fixed delay on power-up only, designed to keep the part
in reset while the power supply stabilizes. With these
two timers on-chip, most applications need no external
reset circuitry.
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 RC oscillator option saves system cost, while the
LP crystal option saves power. A set of configuration
bits are used to select various options.
Additional information on special features is available in
the
(DS33023).
11.1
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 pro-
gram memory location 2007h.
The user will note that address 2007h is beyond the
user program memory space. In fact, it belongs to the
special test/configuration memory space (2000h -
3FFFh), which can be accessed only during program-
ming.
PICmicro
WDTE
Configuration Bits
FOSC1
Mid-Range
FOSC0
bit0
Register:CONFIG
Address2007h
Reference
DS30605A-page 81
Manual,