Datasheet

 1996 Microchip Technology Inc.
Preliminary
DS40122B-page 75
PIC14000
10.0 SPECIAL FEATURES OF THE
CPU
What sets apart a microcontroller from other
processors are special circuits to deal with the needs of
real time applications. The PIC14000 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:
• OSC (oscillator) selection
- Crystal/resonator
- Internal oscillator
• Reset options
- Power-on Reset (POR)
- Power-up Timer (PWRT)
- Oscillator Start-up Timer (OST)
• Interrupts
• Watchdog Timer (WDT)
• SLEEP and HIBERNATE modes
• Code protection
• In-circuit serial programming
These features will be described in the following
sections.
10.1 C
onfiguration 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. In fact, it belongs to the
special test/configuration memory space (2000h -
3FFFh), which can be accessed only during program-
ming.
FIGURE 10-1: CONFIGURATION WORD
2007h Bit 13-8 Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
BITS r CPC r CPP1 CPP0 PWRTE
WDTE r FOSC
Read/Write R/W R/W Reserved R/W R/W R/W R/W Reserved R/W
Erased value 1111111 11
Bit Name Function
B13-B8 r Reserved
B7 CPC
Calibration Space Code Protection Bit
1 = Calibration space is readable and programmable
0 = Calibration space is write protected
B6 r Reserved
B5 CPP1
Program Space Code Protection Bit
1 = Program space is readable and programmable
0 = Program space is read/write protected
B4 CPP0
Program Space Code Protection Bit
1 = Program space is readable and programmable
0 = Program space is read/write protected
B3 PWR
TE
Power-up Timer Enable Bit
1 = Power-up timer is disabled
0 = Power-up timer is enabled
B2 WDTE
Watchdog Timer Enable Bit
1 = WDT is enabled
0 = WDT is disabled
B1 r Reserved
B0 FOSC
Oscillator Selection Bit
1 = IN oscillator (internal)
0 = HS oscillator (crystal/resonator)
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