Datasheet

© 2007 Microchip Technology Inc. Preliminary DS39625C-page 357
PIC18F2585/2680/4585/4680
24.5 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 24-5 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 24-3.
FIGURE 24-5: CODE-PROTECTED PROGRAM MEMORY FOR PIC18F2585/2680/4585/4680
TABLE 24-3: 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* CP2 CP1 CP0
300009h CONFIG5H CPD CPB
— — — — — —
30000Ah CONFIG6L
— — — — WRT3* WRT2 WRT1 WRT0
30000Bh CONFIG6H WRTD WRTB WRTC
— — — — —
30000Ch CONFIG7L
— — — — EBTR3* EBTR2 EBTR1 EBTR0
30000Dh CONFIG7H — EBTRB — — — — — —
Legend: Shaded cells are unimplemented.
* Unimplemented in PIC18FX585 devices; maintain this bit set.
MEMORY SIZE/DEVICE
Block Code Protection
Controlled By:
48 Kbytes
(PIC18F2585/4585)
64 Kbytes
(PIC18F2680/4680)
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)