Datasheet

 2001-2013 Microchip Technology Inc. DS39582C-page 15
PIC16F87XA
2.0 MEMORY ORGANIZATION
There are three memory blocks in each of the
PIC16F87XA devices. The program memory and data
memory have separate buses so that concurrent
access can occur and is detailed in this section. The
EEPROM data memory block is detailed in Section 3.0
“Data EEPROM and Flash Program Memory”.
Additional information on device memory may be found
in the PIC
®
Mid-Range MCU Family Reference Manual
(DS33023).
FIGURE 2-1: PIC16F876A/877A
PROGRAM MEMORY MAP
AND STACK
2.1 Program Memory Organization
The PIC16F87XA devices have a 13-bit program coun-
ter capable of addressing an 8K word x 14 bit program
memory space. The PIC16F876A/877A devices have
8K words x 14 bits of Flash program memory, while
PIC16F873A/874A devices have 4K words x 14 bits.
Accessing a location above the physically implemented
address will cause a wraparound.
The Reset vector is at 0000h and the interrupt vector is
at 0004h.
FIGURE 2-2: PIC16F873A/874A
PROGRAM MEMORY MAP
AND STACK
PC<12:0>
13
0000h
0004h
0005h
Stack Level 1
Stack Level 8
Reset Vector
Interrupt Vector
On-Chip
CALL, RETURN
RETFIE, RETLW
1FFFh
Stack Level 2
Program
Memory
Page 0
Page 1
Page 2
Page 3
07FFh
0800h
0FFFh
1000h
17FFh
1800h
PC<12:0>
13
0000h
0004h
0005h
Stack Level 1
Stack Level 8
Reset Vector
Interrupt Vector
On-Chip
CALL, RETURN
RETFIE, RETLW
1FFFh
Stack Level 2
Program
Memory
Page 0
Page 1
07FFh
0800h
0FFFh
1000h