PIC18F87K22 Datasheet, PDF (86/548 Pages) Microchip Technology – 64/80-Pin, High-Performance, 1-Mbit Enhanced Flash Microcontrollers with 12-Bit A/D and nanoWatt XLP Technology

PIC18F87K22 FAMILY
6.1 Program Memory Organization
PIC18 microcontrollers implement a 21-bit program
counter that 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 PIC18F87K22 family offers a range of
on-chip Flash program memory sizes, from 32 Kbytes
(up to 16,384 single-word instructions) to 128 Kbytes
(65,536 single-word instructions).
• PIC18F65K22 and PIC18F85K22 – 32 Kbytes of
Flash memory, storing up to 16,384 single-word
instructions
• PIC18F66K22 and PIC18F86K22 – 64 Kbytes of
Flash memory, storing up to 32,768 single-word
instructions
• PIC18F67K22 and PIC18F87K22 – 128 Kbytes of
Flash memory, storing up to 65,536 single-word
instructions
The program memory maps for individual family
members are shown in Figure 6-1.
6.1.1 HARD MEMORY VECTORS
All PIC18 devices have a total of three hard-coded
return vectors in their program memory space. The
Reset vector address is the default value to which the
program counter returns on all device Resets. It is
located at 0000h.
PIC18 devices also have two interrupt vector
addresses for handling high-priority and low-priority
interrupts. The high-priority interrupt vector is located at
0008h and the low-priority interrupt vector is at 0018h.
The locations of these vectors are shown, in relation to
the program memory map, in Figure 6-2.
FIGURE 6-2:
HARD VECTOR FOR
PIC18F87K22 FAMILY
DEVICES
Reset Vector
0000h
High-Priority Interrupt Vector 0008h
Low-Priority Interrupt Vector 0018h
On-Chip
Program Memory
Read ‘0’
1FFFFFh
Legend:
(Top of Memory) represents upper boundary
of on-chip program memory space (see
Figure 6-1 for device-specific values).
Shaded area represents unimplemented
memory. Areas are not shown to scale.
DS39960B-page 86
Preliminary
 2010 Microchip Technology Inc.