Datasheet

Table Of Contents
© 2008 Microchip Technology Inc. DS39626E-page 263
PIC18F2525/2620/4525/4620
23.5 Program Verification and
Code Protection
The overall structure of the code protection on the
PIC18 Flash devices differs significantly from other
PIC
®
devices.
The user program memory is divided into five blocks.
One of these is a boot block of 2 Kbytes. The remainder
of the memory is divided into four blocks on binary
boundaries.
Each of the five blocks has three code protection bits
associated with them. They are:
Code-Protect bit (CPn)
Write-Protect bit (WRTn)
External Block Table Read bit (EBTRn)
Figure 23-5 shows the program memory organization
for 48 and 64-Kbyte devices and the specific code
protection bit associated with each block. The actual
locations of the bits are summarized in Table 23-3.
FIGURE 23-5: CODE-PROTECTED PROGRAM MEMORY FOR PIC18F2525/2620/4525/4620
TABLE 23-3: SUMMARY OF CODE PROTECTION REGISTERS
File Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
300008h CONFIG5L —CP3
(1)
CP2 CP1 CP0
300009h CONFIG5H CPD CPB
30000Ah CONFIG6L
—WRT3
(1)
WRT2 WRT1 WRT0
30000Bh CONFIG6H WRTD WRTB WRTC
30000Ch CONFIG7L
EBTR3
(1)
EBTR2 EBTR1 EBTR0
30000Dh CONFIG7H
EBTRB
Legend: Shaded cells are unimplemented.
Note 1: These bits are unimplemented in PIC18FX525 devices; maintain this bit set.
MEMORY SIZE/DEVICE
Block Code Protection
Controlled By:
48 Kbytes
(PIC18F2525/4525)
64 Kbytes
(PIC18F2620/4620)
Address
Range
Boot Block Boot Block
000000h
0007FFh
CPB, WRTB, EBTRB
Block 0 Block 0
000800h
003FFFh
CP0, WRT0, EBTR0
Block 1 Block 1
004000h
007FFFh
CP1, WRT1, EBTR1
Block 2 Block 2
008000h
00B7FFh
CP2, WRT2, EBTR2
Unimplemented
Read ‘0’s
Block 3
00C000h
00FFFFh
CP3, WRT3, EBTR3
Unimplemented
Read ‘0’s
Unimplemented
Read ‘0’s
010000h
1FFFFFh
(Unimplemented Memory Space)