PIC18F1230 MICROCHIP [Microchip Technology], PIC18F1230 Datasheet - Page 47

• Manufacturer Part Number: PIC18F1230
• Description: 18/20/28-Pin, Enhanced Flash Microcontrollers with nanoWatt Technology, High-Performance PWM and A/D
• Manufacturer: MICROCHIP [Microchip Technology]

5.0
There are three types of memory in PIC18 Enhanced
microcontroller devices:
• Program Memory
• Data RAM
• Data EEPROM
As Harvard architecture devices, the data and program
memories use separate busses; this allows for
concurrent access of the two memory spaces. The data
EEPROM, for practical purposes, can be regarded as
a peripheral device, since it is addressed and accessed
through a set of control registers.
Additional detailed information on the operation of the
Flash program memory is provided in Section 6.0
“Flash Program Memory”. Data EEPROM is
discussed separately in Section 7.0 “Data EEPROM
Memory”.
FIGURE 5-1:
© 2006 Microchip Technology Inc.
CALL,RCALL,RETURN
RETFIE,RETLW
MEMORY ORGANIZATION
High Priority Interrupt Vector 0008h
Low Priority Interrupt Vector
Program Memory
Stack Level 31
PIC18F1230
Stack Level 1
Reset Vector
PC<20:0>
Read ‘0’
On-Chip
PROGRAM MEMORY MAP AND STACK FOR PIC18F1230/1330 DEVICES
21
0000h
0018h
0FFFh
1000h
1FFFFFh
200000h
Advance Information
CALL,RCALL,RETURN
RETFIE,RETLW
5.1
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 will return all ‘0’s (a
NOP instruction).
The PIC18F1230 has 4 Kbytes of Flash memory and
can store up to 2,048 single-word instructions. The
PIC18F1330 has 8 Kbytes of Flash memory and can
store up to 4,096 single-word instructions.
PIC18 devices have two interrupt vectors. The Reset
vector address is at 0000h and the interrupt vector
addresses are at 0008h and 0018h.
The program memory maps for PIC18F1230 and
PIC18F1330 devices are shown in Figure 5-1.
High Priority Interrupt Vector 0008h
Low Priority Interrupt Vector
Program Memory Organization
PIC18F1230/1330
Program Memory
PIC18F1330
Stack Level 31
Stack Level 1
Reset Vector
PC<20:0>
On-Chip
Read ‘0’
21
0000h
0018h
1FFFh
2000h
1FFFFFh
200000h
DS39758B-page 45