2000 Microchip Technology Inc.
DS30605C-page 85
PIC16C63A/65B/73B/74B
13.0
SPECIAL FEATURES OF THE
CPU
What sets a microcontroller apart from other proces-
sors are special circuits to deal with the needs of real-
time applications. The PIC16CXX family has a host of
such features intended to maximize system reliability,
minimize cost through elimination of external compo-
nents, provide power saving operating modes and offer
code protection. These are:
• Oscillator selection
• RESET
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
- Brown-out Reset (BOR)
• Interrupts
• Watchdog Timer (WDT)
• SLEEP
• Code protection
• ID locations
• In-Circuit Serial Programming (ICSP)
The PIC16CXX has 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
other is the Power-up Timer (PWRT), which provides a
fixed delay of 72 ms (nominal) on power-up only and is
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, WDT 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.
13.1
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 pro-
gram memory location 2007h.
The user will note that address 2007h is beyond the
user program memory space, and can be accessed
only during programming.
REGISTER 13-1:
CONFIGURATION WORD (CONFIG 2007h)
CP1
CP0
CP1
CP0
CP1
CP0
—
BODEN
CP1
CP0
PWRTE
WDTE FOSC1 FOSC0
bit 13
bit 0
bits 13-8,
5-4
CP1:CP0: Code Protection bits
(2)
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
bit 7
Unimplemented: Read as '1'
bit 6
BODEN: Brown-out Reset Enable bit
(1)
1
= BOR enabled
0
= BOR disabled
bit 3
PWRTE: Power-up Timer Enable bit
(1)
1
= PWRT disabled
0
= PWRT enabled
bit 2
WDTE: Watchdog Timer Enable bit
1
= WDT enabled
0
= WDT disabled
bit 1-0
FOSC1:FOSC0: Oscillator Selection bits
11
= RC oscillator
10
= HS oscillator
01
= XT oscillator
00
= LP oscillator
Note 1: Enabling Brown-out Reset automatically enables Power-up Timer (PWRT), regardless of the value of
PWRTE.
2: All of the CP1:CP0 pairs have to be given the same value to enable the code protection scheme listed.
Summary of Contents for PIC16C63A
Page 4: ...PIC16C63A 65B 73B 74B DS30605C page 4 2000 Microchip Technology Inc NOTES ...
Page 6: ...PIC16C63A 65B 73B 74B DS30605C page 6 2000 Microchip Technology Inc NOTES ...
Page 8: ...PIC16C63A 65B 73B 74B DS30605C page 8 2000 Microchip Technology Inc NOTES ...
Page 28: ...PIC16C63A 65B 73B 74B DS30605C page 28 2000 Microchip Technology Inc NOTES ...
Page 42: ...PIC16C63A 65B 73B 74B DS30605C page 42 2000 Microchip Technology Inc NOTES ...
Page 78: ...PIC16C63A 65B 73B 74B DS30605C page 78 2000 Microchip Technology Inc NOTES ...
Page 112: ...PIC16C63A 65B 73B 74B DS30605C page 112 2000 Microchip Technology Inc NOTES ...
Page 152: ...PIC16C63A 65B 73B 74B DS30605C page 152 2000 Microchip Technology Inc NOTES ...
Page 164: ...PIC16C63A 65B 73B 74B DS30605C page 164 2000 Microchip Technology Inc NOTES ...
Page 174: ...PIC16C63A 65B 73B 74B DS30605C page 174 2000 Microchip Technology Inc NOTES ...
Page 178: ...PIC16C63A 65B 73B 74B DS30605C page 178 2000 Microchip Technology Inc NOTES ...
Page 179: ... 2000 Microchip Technology Inc DS30605C page 179 PIC16C63A 65B 73B 74B NOTES ...
Page 180: ...PIC16C63A 65B 73B 74B DS30605C page 180 2000 Microchip Technology Inc NOTES ...
Page 181: ... 2000 Microchip Technology Inc DS30605C page 181 PIC16C63A 65B 73B 74B NOTES ...
Page 182: ...PIC16C63A 65B 73B 74B DS30605C page 182 2000 Microchip Technology Inc NOTES ...
Page 183: ... 2000 Microchip Technology Inc DS30605C page 183 PIC16C63A 65B 73B 74B NOTES ...