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 : 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 -- 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 : 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