PIC18F87J11_12 Datasheet, PDF (67/466 Pages) Microchip Technology – 64/80-Pin, High-Performance, 1-Mbit Flash Microcontrollers

PIC18F87J11 FAMILY
6.0 MEMORY ORGANIZATION
There are two types of memory in PIC18 Flash
microcontroller devices:
• 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.
Additional detailed information on the operation of the
Flash program memory is provided in Section 7.0
“Flash Program Memory”.
6.1 Program Memory Organization
PIC18 microcontrollers implement a 21-bit Program
Counter (PC) 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 will return all ‘0’s (a
NOP instruction).
The entire PIC18F87J11 family of devices offers three
different on-chip Flash program memory sizes, from
64 Kbytes (up to 16,384 single-word instructions) to
128 Kbytes (65,536 single-word instructions). The
program memory maps for individual family members
are shown in Figure 6-3.
FIGURE 6-1:
MEMORY MAPS FOR PIC18F87J11 FAMILY DEVICES
CALL, CALLW, RCALL,
PC<20:0>
21
RETURN, RETFIE, RETLW,
ADDULNK, SUBULNK
Stack Level 1

Stack Level 31
PIC18FX6J11
On-Chip
Memory
PIC18FX6J16
On-Chip
Memory
PIC18FX7J11
On-Chip
Memory
000000h
Config. Words
Config. Words
00FFFFh
017FFFh
Config. Words _01FFFFh
Unimplemented
Read as ‘0’
Unimplemented
Read as ‘0’
Unimplemented
Read as ‘0’
Note:
1FFFFFF
Sizes of memory areas are not to scale. Sizes of program memory areas are enhanced to show detail.
 2007-2012 Microchip Technology Inc.
DS39778E-page 67