
2011 Microchip Technology Inc.
DS39932D-page 77
PIC18F46J11 FAMILY
6.0
MEMORY ORGANIZATION
There are two types of memory in PIC18 Flash
microcontrollers:
Program Memory
Data RAM
As Harvard architecture devices, the data and program
memories use separate busses; this allows for
concurrent access of the two memory spaces.
provides
additional information on the operation of the Flash
program memory.
6.1
Program Memory Organization
PIC18 microcontrollers implement a 21-bit program
counter, which is capable of addressing a 2-Mbyte
program memory space. Accessing a location between
the upper boundary of the physically implemented
memory and the 2-Mbyte address returns all ‘0’s (a
NOP
instruction).
The PIC18F46J11 family offers a range of on-chip
Flash program memory sizes, from 16 Kbytes (up to
8,192
single-word
instructions)
to
64 Kbytes
(32,768 single-word instructions).
individual family devices.
FIGURE 6-1:
MEMORY MAPS FOR PIC18F46J11 FAMILY DEVICES
Note:
Sizes of memory areas are not to scale. Sizes of program memory areas are enhanced to show detail.
Unimplemented
Read as ‘0’
Unimplemented
Read as ‘0’
Unimplemented
Read as ‘0’
000000h
1FFFFFF
003FFFh
007FFFh
00FFFFh
PC<20:0>
Stack Level 1
Stack Level 31
CALL, CALLW, RCALL,
RETURN, RETFIE, RETLW,
21
User
M
e
mory
S
pace
On-Chip
Memory
On-Chip
Memory
On-Chip
Memory
ADDULNK, SUBULNK
Config. Words
PIC18FX4J11
PIC18FX5J50
PIC18FX6J11