PIC16LF1904 Datasheet, PDF (46/288 Pages) Microchip Technology – 28/40/44-Pin Flash-Based, 8-Bit CMOS Microcontrollers with LCD Driver and nanoWatt XLP Technology

PIC16LF1904/6/7
4.2 Code Protection
Code protection allows the device to be protected from
unauthorized access. Program memory protection is
controlled independently. Internal access to the
program memory is unaffected by any code protection
setting.
4.2.1 PROGRAM MEMORY PROTECTION
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 setting. See Section 4.3 “Write
Protection” for more information.
4.3 Write Protection
Write protection allows the device to be protected from
unintended self-writes. Applications, such as boot
loader 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 User ID
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 10.4 “User ID, Device ID and Configuration
Word Access” for more information on accessing
these memory locations. For more information on
checksum
calculation,
see
the
“PIC16F193X/LF193X/PIC16F194X/LF194X/PIC16LF
190X Memory
(DS41397).
Programming
Specification”
DS41569A-page 46
Preliminary
 2011 Microchip Technology Inc.