Datasheet

MCP19111
DS22331A-page 80  2013 Microchip Technology Inc.
12.2 Code Protection
Code protection allows the device to be protected from
unauthorized access. Internal access to the program
memory is unaffected by any code protection setting.
12.2.1 PROGRAM MEMORY PROTECTION
The entire program memory space is protected from
external reads and writes by the CP
bit in the
Configuration Word. When CP
= 0, external reads and
writes of the 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 12.3
“Write Protection” for more information.
12.3 Write Protection
Write protection allows the device to be protected from
unintended self-writes. Applications, such as
bootloader software, can be protected while allowing
other regions of the program memory to be modified.
The WRT<1:0> bits in the Configuration Word define
the size of the program memory block that is protected.
12.4 ID Locations
Four memory locations (2000h – 2003h) are
designated as ID locations where the user can store
checksum or other code identification numbers. These
locations are not accessible during normal execution
but are readable and writable during Program/Verify
mode. Only the Least Significant 7 bits of the ID
locations are reported when using MPLAB Integrated
Development Environment (IDE).
12.5 Device ID and Revision ID
The memory location 2006h is where the Device ID and
Revision ID are stored. The upper nine bits hold the
Device ID. The lower five bits hold the Revision ID.
Development tools, such as device programmers and
debuggers, may be used to read the Device ID and
Revision ID.
REGISTER 12-2: DEVICEID: DEVICE ID REGISTER
(1)
RRR R RR
DEV<8:3>
bit 13 bit 8
RRRRRRRR
DEV<2:0> REV<4:0>
bit 7 bit 0
Legend:
R = Readable bit P = Programmable bit U = Unimplemented bit, read as ‘0’
-n = Value at POR ‘1’ = Bit is set ‘0’ = Bit is cleared x = Bit is unknown
bit 13-5 DEV<8:0>: Device ID bits
bit 4-0 REV<4:0>: Revision ID bits
These bits are used to identify the revision.
Note 1: This location cannot be written.
Device
DEVICEID<13:0> Values
DEV<8:0> REV<4:0>
MCP19111 10 1111 100 x xxxx