PIC18F1XK22 Datasheet, PDF (27/388 Pages) Microchip Technology – 20-Pin Flash Microcontrollers with nanoWatt XLP Technology

PIC18F1XK22/LF1XK22
3.0 MEMORY ORGANIZATION
There are three types of memory in PIC18 Enhanced
microcontroller devices:
• Program Memory
• Data RAM
• Data EEPROM
As Harvard architecture devices, the data and program
memories use separate busses; this allows for concur-
rent access of the two memory spaces. The data
EEPROM, for practical purposes, can be regarded as
a peripheral device, since it is addressed and accessed
through a set of control registers.
Additional detailed information on the operation of the
Flash program memory is provided in Section 4.0
“Flash Program Memory”. Data EEPROM is
discussed separately in Section 5.0 “Data EEPROM
Memory”.
3.1 Program Memory Organization
PIC18 microcontrollers implement a 21-bit program
counter, which is capable of addressing a 2-Mbyte
Program Memory (PC) space. Accessing a location
between the upper boundary of the physically
implemented memory and the 2-Mbyte address will
return all ‘0’s (a NOP instruction).
This family of devices contain the following:
• PIC18F13K22/LF13K22: 8 Kbytes of Flash Mem-
ory, up to 4,096 single-word instructions
• PIC18F14K22/LF14K22: 16 Kbytes of Flash Mem-
ory, up to 8,192 single-word instructions
PIC18 devices have two interrupt vectors and one
Reset vector. The Reset vector address is at 0000h
and the interrupt vector addresses are at 0008h and
0018h.
The program memory map for PIC18F1XK22/
LF1XK22 devices is shown in Figure 3-1. Memory
block details are shown in Figure 22-2.
FIGURE 3-1:
PROGRAM MEMORY MAP AND STACK FOR PIC18F1XK22/LF1XK22 DEVICES
PC<20:0>
CALL,RCALL,RETURN
21
RETFIE,RETLW
Stack Level 1



Stack Level 31
Reset Vector
High Priority Interrupt Vector
On-Chip
Program Memory
1FFFh
2000h
PIC18F13K22/
LF13K22
Low Priority Interrupt Vector
On-Chip
Program Memory
3FFFh
4000h
PIC18F14K22/
LF14K22
0000h
0008h
0018h
Read ‘0’
Read ‘0’
1FFFFFh
200000h
 2010 Microchip Technology Inc.
Preliminary
DS41365D-page 27