PIC12F1840 MICROCHIP [Microchip Technology], PIC12F1840 Datasheet - Page 45

• Manufacturer Part Number: PIC12F1840
• Description: 8-Pin Flash Microcontrollers with nanoWatt XLP Technology
• Manufacturer: MICROCHIP [Microchip Technology]

4.2
Code protection allows the device to be protected from
unauthorized access. Program memory protection and
data EEPROM protection are controlled independently.
Internal access to the program memory and data
EEPROM are unaffected by any code protection
setting.
4.2.1
The entire program memory space is protected from
external reads and writes by the CP bit in Configuration
Word 1. When CP = 0, external reads and writes of
program memory are inhibited and a read will return all
‘0’s. The CPU can continue to read program memory,
regardless of the protection bit settings. Writing the
program memory is dependent upon the write
protection
Protection”
4.2.2
The entire data EEPROM is protected from external
reads and writes by the CPD bit. When CPD = 0,
external reads and writes of data EEPROM are
inhibited. The CPU can continue to read and write data
EEPROM regardless of the protection bit settings.
4.3
Write protection allows the device to be protected from
unintended
bootloader software, can be protected while allowing
other regions of the program memory to be modified.
The WRT<1:0> bits in Configuration Word 2 define the
size of the program memory block that is protected.
4.4
Four memory locations (8000h-8003h) are designated as
ID locations where the user can store checksum or other
code identification numbers. These locations are
readable and writable during normal execution. See
Section 11.5 “User ID, Device ID and Configuration
Word Access”
memory locations. For more information on checksum
calculation, see the “PIC16F/LF1847/PIC12F/LF1840
Memory Programming Specification” (DS41439).
 2011 Microchip Technology Inc.
Code Protection
Write Protection
User ID
PROGRAM MEMORY PROTECTION
DATA EEPROM PROTECTION
for more information.
setting.
self-writes.
for more information on accessing these
See
Applications,
Section 4.3
such
“Write
Preliminary
as
PIC12F/LF1840
DS41441A-page 45