PIC16F872
2.0
MEMORY ORGANIZATION
2.2
Data Memory Organization
There are three memory blocks in each of these
PICmicro
®
MCUs. 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
Additional information on device memory may be found
in the PICmicro™ Mid-Range Reference Manual,
(DS33023).
The data memory is partitioned into multiple banks
which contain the General Purpose Registers and the
Special Function Registers. Bits RP1(STATUS<6>)
and RP0 (STATUS<5>) are the bank select bits.
RP<1:0>
00
01
10
11
Bank
0
1
2
3
2.1
Program Memory Organization
The PIC16F872 devices have a 13-bit program counter
capable of addressing an 8K x 14 program memory
space. The PIC16F872 device has 2K x 14 words of
FLASH program memory. Accessing a location above
the physically implemented address will cause a wrap-
around.
The reset vector is at 0000h and the interrupt vector is
at 0004h.
Each bank extends up to 7Fh (128 bytes). The lower
locations of each bank are reserved for the Special
Function Registers. Above the Special Function Regis-
ters are General Purpose Registers, implemented as
static RAM. All implemented banks contain Special
Function Registers. Some “high use” Special Function
Registers from one bank may be mirrored in another
bank for code reduction and quicker access.
Note:
2.2.1
EEPROM Data Memory description can be
found in Section 4.0 of this Data Sheet
GENERAL PURPOSE REGISTER FILE
FIGURE 2-1:
PIC16F872 PROGRAM
MEMORY MAP AND STACK
PC<12:0>
The register file can be accessed either directly, or indi-
rectly through the File Select Register FSR.
13
CALL, RETURN
RETFIE, RETLW
Stack Level 1
Stack Level 2
Stack Level 8
Reset Vector
0000h
Interrupt Vector
On-Chip
Program
Memory
0004h
0005h
Page 0
07FFh
0800h
1FFFh
©
1999 Microchip Technology Inc.
Preliminary
DS30221A-page 7
MICROCHIP [ MICROCHIP TECHNOLOGY ]
