EMBEDDED SYSTEM
CMC , NOIDA
EMBEDDED SYSTEM :
1.
An embedded system is a computer system designed to
perform one or a few dedicated functions , often with real-time
computing constraints.
2.
It is embedded as part of a complete device often including
hardware and software parts.
3.
Embedded system is dedicated to specific tasks, design
engineers can optimize it reducing the size and cost of the
product and increasing the reliability and performance. Some
embedded systems are mass-produced, benefiting from
economies of scale.
DIFFERENCE BETWEEN
MICROPROCESSOR AND MICROCONTROLLOR
µp
RAM
ROM
I/O
PORT
TIMER
SERIAL
COM
PORT
GENERAL PURPOSE
MICROPROCESSOR
SYSTEM
CPU
CPU
RAM
ROM
MICROCONTROLLOR
I/O PORT
TIMER
SERIAL
COM
PORT
8051 MICROCONTROLLOR :
1. The Intel 8051 is a Harvard architecture, single chip microcontroller (µC) which
was developed by Intel in 1980 for use in embedded systems.
2. High level languages such as Forth, BASIC, Pascal/Object Pascal, PL/M and
Modula 2 are available for the 8051, but they are less widely used than C and
assembly.
IMPORTANT FEATURES :
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IT PROVIDES MANY FUNCTIONS (CPU,RAM,ROM,I/O,INTERRUPT LOGIC,TIMER,ETC)
IN A SINGLE PACKAGE.
2. 8-BIT ALU,ACCUMULATOR AND REGISTERS ; IT IS AN 8-BIT MICROCONTROLLOR.
8-BIT DATA BUS.
16-BIT ADDRESS BUS.
ON CHIP RAM – 128 BYTES.
ON CHIP ROM – 4 KB .
FOUR BIT BI-DIRECTIONAL I/O PORT.
UART.
TWO 16-BIT COUNTER / TIMER.
TWO –LEVEL INTERRUPT PRIORITY.
POWER SAVING MODE.
INSTRUCTION SET :
1. Arithmetic Operation
2. Logical Operations
3. Data Transfer Operations
4. Single Bit (Boolean Variable) Operations
5. Program Flow Control .
PIN DIAGRAM OF 8051 :
MOST WIDELY USED REGISTER OF THE 8051 :
 A (ACCUMULATOR) – 8 BITS
 B , R0 , R1 , R2 , R3 , R4 , R5 , R6 , R7 – 8 BITS
 DPTR ( DATA POINTER ) – 16 BITS
 PC ( PROGRAM COUNTER ) – 16 BITS
FLAG REGISTER :
CY
 CY - AC - F0 - RS1 - RS0 - OV - __ -P
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AC
F0
RS1
CARRY FLAG
AUXILIARY FLAG
USE OF GENERAL PURPOSE
REGISTER BANK SELECTOR BIT 1
REGISTER BANK SELECTOR BIT 0
OVER FLOW FLAG
USER DEFINABLE BIT
PARITY FLAG
RS0
OV
__
P
ADDRESSING MODES :
 IMMEDIATE ADDRESSING MODE
 REGISTER ADDRESSING MODE
 DIRECT ADDRESSING MODE
 REGISTER INDIRECT ADDRESSING MODE
 INDEXED ADDRESSING MODE
OUR PROJECT
EVM(electronics voting machine)
EQUIPMENT USED IN EVM :
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PCB (PRINTED CIRCUIT BOARD) -- 2
9 VOLT BATTERY
LM 7805
VOLTAGE REGULATOR
AT89C51 MICROCONTROLLER
CAPCITOR
RESISTOR
DIP SWITCH
OSCILLATOR
LCD ( 2 LINE * 16 CHARACTERS )
DATA BUS
INTERFACING :
THE MICROPROCESSOR AND MICROPROCESSOR COMBINED WITH OTHER
DEVICES , FORM A MICROCOMPUTER.
MICROCONTROLLOR AND MICROPROCESSOR IS HEART OF A MICROCOMPUTER.
BASICALLY ,WE ARE USING TWO TYPE OF INTERFACING :
LCD INTERFACING
KEYBOARD INTERFACING
LCD INTERFACING
KEYBOARD INTERFACING