PIC18F1220 MICROCHIP [Microchip Technology], PIC18F1220 Datasheet - Page 43

• Manufacturer Part Number: PIC18F1220
• Description: 18/20/28-Pin High-Performance, Enhanced Flash Microcontrollers with 10-bit A/D and nanoWatt Technology
• Manufacturer: MICROCHIP [Microchip Technology]

5.0
There are three memory types in Enhanced MCU
devices. These memory types are:
• Program Memory
• Data RAM
• Data EEPROM
Data and program memory use separate busses,
which allows for concurrent access of these types.
Additional detailed information for Flash program mem-
ory and data EEPROM is provided in Section 6.0
“Flash Program Memory” and Section 7.0 “Data
EEPROM Memory”, respectively.
FIGURE 5-1:
 2004 Microchip Technology Inc.
CALL,RCALL,RETURN
RETFIE,RETLW
MEMORY ORGANIZATION
High Priority Interrupt Vector 0008h
Low Priority Interrupt Vector
Program Memory
Stack Level 31
Stack Level 1
Reset Vector
PC<20:0>
Read ‘0’
On-Chip
PROGRAM MEMORY MAP
AND STACK FOR
PIC18F1220
21
0000h
0018h
0FFFh
1000h
1FFFFFh
200000h
5.1
A 21-bit program counter is capable of addressing the
2-Mbyte program memory space. Accessing a location
between the physically implemented memory and the
2-Mbyte address will cause a read of all ‘0’s (a NOP
instruction).
The PIC18F1220 has 4 Kbytes of Flash memory and
can store up to 2,048 single-word instructions.
The PIC18F1320 has 8 Kbytes of Flash memory and
can store up to 4,096 single-word instructions.
The Reset vector address is at 0000h and the interrupt
vector addresses are at 0008h and 0018h.
The program memory maps for the PIC18F1220 and
PIC18F1320 devices are shown in Figure 5-1 and
Figure 5-2, respectively.
FIGURE 5-2:
CALL,RCALL,RETURN
RETFIE,RETLW
Program Memory Organization
PIC18F1220/1320
High Priority Interrupt Vector 0008h
Low Priority Interrupt Vector
Program Memory
Stack Level 31
Reset Vector
Stack Level 1
PC<20:0>
On-Chip
Read ‘0’
PROGRAM MEMORY MAP
AND STACK FOR
PIC18F1320
21
0000h
0018h
1FFFh
2000h
1FFFFFh
200000h
DS39605C-page 41