PIC18F2331 MICROCHIP [Microchip Technology], PIC18F2331 Datasheet - Page 59

• Manufacturer Part Number: PIC18F2331
• Description: 28/40/44-Pin Enhanced Flash Microcontrollers with nanoWatt Technology, High Performance PWM and A/D
• 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:
 2003 Microchip Technology Inc.
CALL,RCALL,RETURN
RETFIE,RETLW
MEMORY ORGANIZATION
High Priority Interrupt Vector LSb
Low Priority Interrupt Vector LSb
Program Memory
Reset Vector LSb
On-Chip Flash
Stack Level 31
Stack Level 1
PC<20:0>
PROGRAM MEMORY MAP
AND STACK FOR
PIC18F2331/4331
Read ‘0’s
Unused -
21
000018h
1FFFFFh
000000h
000008h
001FFFh
002000h
PIC18F2331/2431/4331/4431
Preliminary
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 PIC18F2331 and PIC18F4331 each have
8 Kbytes of Flash memory and can store up to 4,096
single-word instructions.
The PIC18F2431 and PIC18F4431 each have
16 Kbytes of Flash memory and can store up to 8,192
single-word instructions.
The Reset vector address is at 000000h and the
interrupt vector addresses are at 000008h and
000018h.
The Program Memory Maps for PIC18F2X31 and
PIC18F4X31 devices are shown in Figure 5-1 and
Figure 5-2, respectively.
FIGURE 5-2:
CALL,RCALL,RETURN
RETFIE,RETLW
Program Memory Organization
High Priority Interrupt Vector LSb
Low Priority Interrupt Vector LSb
Reset Vector LSb
Program Memory
Stack Level 31
On-Chip Flash
Stack Level 1
PROGRAM MEMORY MAP
AND STACK FOR
PIC18F2431/4431
PC<20:0>
Unused -
Read ‘0’s
21
DS39616B-page 57
003FFFh
004000h
1FFFFFh
000018h
000000h
000008h