PIC18F258-I/SP View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC18F258-I/SP

28/40-Pin High-Performance, Enhanced Flash Microcontrollers with CAN Module

Microchip Technology 

PIC18FXX8

24.4 Program Verification and

Code Protection

The overall structure of the code protection on the

PIC18 Flash devices differs significantly from other

PICmicro devices.

The user program memory is divided into five blocks.

One of these is a boot block of 512 bytes. The remain-

der 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 24-3 shows the program memory organization

for 16 and 32-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 24-3:

CODE-PROTECTED PROGRAM MEMORY FOR PIC18FXX8

MEMORY SIZE/DEVICE

16 Kbytes

(PIC18FX48)

32 Kbytes

(PIC18FX58)

Address

Range

Block Code Protection

Controlled By:

Boot Block

Block 0

Boot Block

Block 0

000000h

0001FFh

000200h

001FFFh

CPB, WRTB, EBTRB

CP0, WRT0, EBTR0

Block 1

Unimplemented

Read ‘0’s

Block 1

Block 2

002000h

003FFFh

004000h

005FFFh

CP1, WRT1, EBTR1

CP2, WRT2, EBTR2

Unimplemented

Read ‘0’s

Block 3

006000h

007FFFh

008000h

CP3, WRT3, EBTR3

Unimplemented

Read ‘0’s

Unimplemented

Read ‘0’s

(Unimplemented Memory Space)

1FFFFFh

TABLE 24-3: SUMMARY OF CODE PROTECTION REGISTERS

File Name

Bit 7

Bit 6

Bit 5

Bit 4

Bit 3

300008h CONFIG5L

—

—

—

—

CP3

300009h CONFIG5H CPD

CPB

—

—

—

30000Ah CONFIG6L

—

—

—

—

WRT3

30000Bh CONFIG6H WRTD WRTB WRTC

—

—

30000Ch CONFIG7L

—

—

—

—

EBTR3

30000Dh CONFIG7H —

EBTRB

—

—

—

Legend: Shaded cells are unimplemented.

Bit 2

CP2

—

WRT2

—

EBTR2

—

Bit 1

CP1

—

WRT1

—

EBTR1

—

Bit 0

CP0

—

WRT0

—

EBTR0

—

DS41159E-page 276

© 2006 Microchip Technology Inc.

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