PIC16F871-I View Datasheet(PDF) - Microchip Technology

Part Name

Description

Manufacturer

PIC16F871-I

28/40-Pin, 8-Bit CMOS FLASH Microcontrollers

Microchip Technology 

2.0 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

Section 4.0.

Additional information on device memory may be found

in the PICmicro™ Mid-Range Reference Manual,

(DS33023).

2.1 Program Memory Organization

The PIC16F870/871 devices have a 13-bit program

counter capable of addressing an 8K x 14 program

memory space. The PIC16F870/871 devices have 2K

x 14 words of FLASH program memory. 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 2-1: PIC16F870/871 PROGRAM

MEMORY MAP AND STACK

PC<12:0>

CALL, RETURN

13

RETFIE, RETLW

Stack Level 1

Stack Level 2

Stack Level 8

Reset Vector

0000h

PIC16F870/871

2.2 Data Memory Organization

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

Bank

0

01

1

10

2

11

3

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: EEPROM Data Memory description can be

found in Section 4.0 of this Data Sheet

2.2.1 GENERAL PURPOSE REGISTER FILE

The register file can be accessed either directly, or indi-

rectly through the File Select Register FSR.

On-Chip

Program

Memory

Interrupt Vector

Page 0

0004h

0005h

07FFh

0800h

1FFFh

© 1999 Microchip Technology Inc.

Preliminary

DS30569A-page 11

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