PIC18F86K22-I Datasheet, PDF (88/550 Pages) Microchip Technology – 64/80-Pin, High-Performance, 1-Mbit Enhanced Flash Microcontrollers

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.
DS39960D-page 88
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