
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
Conguration Bits
The conguration bits can be programmed (read as '0')
or left unprogrammed (read as '1') to select various
device congurations. 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/conguration 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
Reserved
R/W
Reserved
R/W
Erased value
1
111
1
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
PWRTE
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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