Datasheet

ManualsBrandsMICROCHIP TECHNOLOGY ManualsMicrocontrollers, Microprocessors & QuartzesEmbedded microcontroller SSOP 28 8-Bit 20 MHz I/O number 22

 2002 Microchip Technology Inc. DS30325B-page 13

PIC16F7X

2.0 MEMORY ORGANIZATION

There are two 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

Program Memory can be read internally by user code

(see Section 3.0).

Additional information on device memory may be found

in the PICmicro Mid-Range Reference Manual

(DS33023).

2.1 Program Memory Organization

The PIC16F7X devices have a 13-bit program counter

capable of addressing an 8K word x 14-bit program

memory space. The PIC16F77/76 devices have

8K words of FLASH program memory and the

PIC16F73/74 devices have 4K words. The program

memory maps for PIC16F7X devices are shown in

Figure 2-1. 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.

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:

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 frequently used Special

Function Registers from one bank may be mirrored in

another bank for code reduction and quicker access.

2.2.1 GENERAL PURPOSE REGISTER

FILE

The register file (shown in Figure 2-2 and Figure 2-3)

can be accessed either directly, or indirectly, through

the File Select Register FSR.

FIGURE 2-1: PROGRAM MEMORY MAPS AND STACKS FOR PIC16F7X DEVICES

RP1:RP0 Bank

00 0

01 1

10 2

11 3

PC<12:0>

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

17FFh

1800h