PIC18F010 datasheet(25/176 Pages) MICROCHIP

25 / 176 page

 2001 Microchip Technology Inc.

Preliminary

DS41142A-page 23

PIC18F010/020

4.0

MEMORY ORGANIZATION

There are three memory blocks in PIC18F010/020

Enhanced MCU devices. These memory blocks are:

• Program Memory

• Data Memory

• EEPROM Data Memory

The EEPROM Data Memory is described in detail in

Section 5.0.

4.1

Program Memory Organization

The PIC18F010/020 devices have a 21-bit program

counter. Bits 12 through 16 are implemented as ‘0’

internally; therefore, accessing locations 0x01000

through 0x1FFFF actually mirror what is present in pro-

gram memory from 0x0000 through 0x0FFF. The

PIC18F010 device reads all zeros (NOP) from 0x0800

through 0x0FFF.

PIC18F020 has 4 Kbytes of FLASH program memory,

while PIC18F010 has 2 Kbytes of FLASH program

memory. This means the PIC18F020 can store up to 2K

of single word instructions, and the PICF18010 can

store up to 1K of single word instructions.

The RESET vector address is at 0000h and the inter-

rupt vector addresses are at 0008h and 0018h. 0008h

is the high priority interrupt and 0018h is the low priority

interrupt vector.

Figure 4-1 shows the Program Memory Map for

PIC18F010 and Figure 4-2 shows the Program Mem-

ory Map for PIC18F020 devices.

PIC18F010 Datasheet(PDF) 25 Page - Microchip Technology