17321411 microprocessor 8085 by shaheen fatima

8/14/2019 17321411 Microprocessor 8085 by Shaheen Fatima

http://slidepdf.com/reader/full/17321411-microprocessor-8085-by-shaheen-fatima 1/17

11

SEMINAR PRESENTED BY:SEMINAR PRESENTED BY:

Mrs. SHAHEEN FATIMAMrs. SHAHEEN FATIMALECTURER IN ELECTRONICSLECTURER IN ELECTRONICS

GOVT DEGREE SCIENCE COLLEGEGOVT DEGREE SCIENCE COLLEGE

TUMKURU.TUMKURU.KARNATAKA STATE.KARNATAKA STATE.



22

Introduction to MicroprocessorIntroduction to Microprocessor The Microprocessor is an electronic logic device having The Microprocessor is an electronic logic device having

computational and data manipulation capabilities.computational and data manipulation capabilities. Due to great invention in semiconductor fabricationDue to great invention in semiconductor fabrication

technique, it became possible to fabricate the whole centraltechnique, it became possible to fabricate the whole central

processing unit of computer on a single small integratedprocessing unit of computer on a single small integrated

chip called as microprocessor.chip called as microprocessor.

The computer having microprocessor as central processing The computer having microprocessor as central processing

unit are called as microcomputers.unit are called as microcomputers.

A desktop computer and portable( or mobile ) computersA desktop computer and portable( or mobile ) computers

like laptop, notebook, palmtop etc, contains microprocessorlike laptop, notebook, palmtop etc, contains microprocessor

as a CPU and hence they come under the category of as a CPU and hence they come under the category of microcomputer.microcomputer.

A microprocessor ( or computer ) understands information'sA microprocessor ( or computer ) understands information's

composed of only 0s and 1s. It uses binary numbers for itcomposed of only 0s and 1s. It uses binary numbers for it

operations. A binary digit is know as a bit. A group of 8 – bitoperations. A binary digit is know as a bit. A group of 8 – bit

is called a byte.is called a byte.



4401/28/1001/28/10



55

Features of 8085 Features of 8085

Intel 8085 is an 8 – bit, NMOS microprocessorIntel 8085 is an 8 – bit, NMOS microprocessor It is a 40 pin IC package fabricated on a singleIt is a 40 pin IC package fabricated on a single

LSI chip.LSI chip.

The Intel 8085 uses single of + 5V dc supplyThe Intel 8085 uses single of + 5V dc supplyfor its operation.for its operation.

Its clock speed is about 3MHz.Its clock speed is about 3MHz.

It has 80 basic instructions and 246 0pcodes.It has 80 basic instructions and 246 0pcodes.



66

croprocessorArchitectureArchitecture



77

ARITHICTURE FEATURES of 8085 ARITHICTURE FEATURES of 8085

: 1 :: 1 : It consists of three main sections.It consists of three main sections.

An arithmetic and logic unit (ALU ).An arithmetic and logic unit (ALU ).

Timing and control unit.Timing and control unit.

Set of registers.Set of registers.

AN ARITHIMETIC AND LOGIC UNIT. ( ALU )AN ARITHIMETIC AND LOGIC UNIT. ( ALU ) ALU performs the following arithmetic and logicalALU performs the following arithmetic and logical

operations.operations.

1) Addition. 2 ). Subtraction. 3 ). Logical AND. 4 ) Logical1) Addition. 2 ). Subtraction. 3 ). Logical AND. 4 ) Logical

OR. 5 ). Logical exclusive.6 ). Complement. 7 ).OR. 5 ). Logical exclusive.6 ). Complement. 7 ).

Increment. 8 ) Decrement. 9 ).Left Shift, Rotate left,Increment. 8 ) Decrement. 9 ).Left Shift, Rotate left,

Rotate right.Rotate right.

Clear, etc.Clear, etc.



88

: 2 :: 2 : TIMING AND CONTROL UNIT TIMING AND CONTROL UNIT :: The timing and control unit is a section of the CPU. Its generates The timing and control unit is a section of the CPU. Its generates

timing and control signals which are necessary for the executiontiming and control signals which are necessary for the executionof instructions. It controls data flow between CPU andof instructions. It controls data flow between CPU andperipherals. It controls the entire operations of theperipherals. It controls the entire operations of themicroprocessor and peripherals connected to it. Thus it is seenmicroprocessor and peripherals connected to it. Thus it is seenthat timing and control unit of the CPU acts as the brain of thethat timing and control unit of the CPU acts as the brain of thecomputer system.computer system.

REGISTERS :REGISTERS : Registers are used by the microprocessor for temporary storageRegisters are used by the microprocessor for temporary storage

and manipulation of data and instructions. Data remains in theand manipulation of data and instructions. Data remains in theregisters till they are sent to the memory or I/O devices.registers till they are sent to the memory or I/O devices.

Intel 8085 microprocessor has the following registers,Intel 8085 microprocessor has the following registers, 1) One 8 – bit accumulator ( ACC ) ie. Register A.1) One 8 – bit accumulator ( ACC ) ie. Register A. 2) Six 8 – bit general purpose registers. B,C,D,E, H,& L.2) Six 8 – bit general purpose registers. B,C,D,E, H,& L. 3) One 16 – bit stack pointer, ie. SP.3) One 16 – bit stack pointer, ie. SP. 4) One 16 – bit program Counter, ie, PC.4) One 16 – bit program Counter, ie, PC. 5) Instruction register.5) Instruction register. 6) Status register.6) Status register. 7) Temporary register.7) Temporary register.



99

8085 Pin Description8085 Pin Description



1010



1111

Pin Diagram of 8085Pin Diagram of 8085

: 1 :: 1 : From this logic pin out of the 8085 microprocessor. All theFrom this logic pin out of the 8085 microprocessor. All the

signals can be classified into six groups.signals can be classified into six groups. 1). High order address bus.1). High order address bus. 2). Multiplexed Address/data bus.2). Multiplexed Address/data bus. 3). Power supply & frequency signals.3). Power supply & frequency signals. 4). Externally initiated signals.4). Externally initiated signals. 5). Serial I/O ports.5). Serial I/O ports. HIGH ORDER ADDRESS BUSHIGH ORDER ADDRESS BUS:: The 8085 has sight signal lines, A18------A15 which are The 8085 has sight signal lines, A18------A15 which are

unidirectional and used as the high order address bus.unidirectional and used as the high order address bus. MULTIPLEXED ADDRESS / DATA BUS :MULTIPLEXED ADDRESS / DATA BUS : The signal lines AD7---------AD0 are bidirectional, they serve a The signal lines AD7---------AD0 are bidirectional, they serve a

dual purpose. They are used as the low order address bus asdual purpose. They are used as the low order address bus aswell as the data bus.well as the data bus.



1212

: 2 :: 2 : CONTROL AND STATUS SIGNALS :CONTROL AND STATUS SIGNALS :

This group of signals includes two controls signalsThis group of signals includes two controls signals

( RD & WR ), three status signals ( IO/M, S1 & S0 ) to( RD & WR ), three status signals ( IO/M, S1 & S0 ) to

identify the nature of the operation, and one specialidentify the nature of the operation, and one special

signal (ALE) to indicate the beginning of thesignal (ALE) to indicate the beginning of the

operation.operation.

POWER SUPPLY AND CLOCK FREQUENCY POWER SUPPLY AND CLOCK FREQUENCY ..

VCC + 5V Power supply , VSS =ground reference,VCC + 5V Power supply , VSS =ground reference,X1,X2 = These are terminals to be connected to anX1,X2 = These are terminals to be connected to an

external crystals oscillator which drives an internalexternal crystals oscillator which drives an internal

circuitry of the microprocessor to produce a suitablecircuitry of the microprocessor to produce a suitable

clock for the operation of microprocessor. This signalclock for the operation of microprocessor. This signal

can be used as the system clock for the devices.can be used as the system clock for the devices.

SERIAL I/0 PORT :SERIAL I/0 PORT :

The 8085 has two signals to implement the serialThe 8085 has two signals to implement the serial

transmission, SID ( Serial I/P Data ) and SOD ( Serialtransmission, SID ( Serial I/P Data ) and SOD ( Serial

O/P Data)O/P Data)



1313

Intel 8085 InstructionsIntel 8085 Instructions



1414

Intel 8085 Instructions setIntel 8085 Instructions set An instruction is a command given to theAn instruction is a command given to the

computer to perform a specified operationcomputer to perform a specified operationon given data.on given data. 8085 has 80 basic instructions & 2468085 has 80 basic instructions & 246

Opcodes each instruction contain two parts,Opcodes each instruction contain two parts,Operation code and Operand.Operation code and Operand.

The first part of an instruction whichThe first part of an instruction whichspecifies the task to be performed by thespecifies the task to be performed by thecomputer is called Opcode.computer is called Opcode.

The second part of the instruction is theThe second part of the instruction is the

data to be operated on and it is calleddata to be operated on and it is calledOperand.Operand.

Example : ADD }-– Opcode, B }-– Operand.Example : ADD }-– Opcode, B }-– Operand. MVI }-– Opcode B}---Operand.MVI }-– Opcode B}---Operand.



1515

Programming of Microprocessor.Programming of Microprocessor. The simplest symbolic language used forThe simplest symbolic language used for

microprocessor is assembly language. The symbolsmicroprocessor is assembly language. The symbolsare called as mnemonics. The language written inare called as mnemonics. The language written in

the form of mnemonics is called as assemblythe form of mnemonics is called as assembly level language. The mnemonics are alphanumericlanguage. The mnemonics are alphanumericrepresentation of instructions .ie. It is anrepresentation of instructions .ie. It is ancombination of letters to indicate the operation of combination of letters to indicate the operation of the instructions.the instructions.

The assembly language program for the additionThe assembly language program for the additionof two numbers placed in two consecutive memoryof two numbers placed in two consecutive memorylocations, 2501H and 2502H & the sum is stored inlocations, 2501H and 2502H & the sum is stored inthe memory location 2503Hthe memory location 2503H

Mnemonics: Opcode :Mnemonics: Opcode : Operand.Operand. LX1LX1 H,2501H.H,2501H. MOVMOV A,MA,M INXINX HH ADDADD MM STASTA 2501H.2501H.



1616

Microprocessor ApplicationsMicroprocessor Applications

Today microprocessor based systems areToday microprocessor based systems areused in almost every sphere of life. Theirused in almost every sphere of life. Theirapplications are increasing at very fast rateapplications are increasing at very fast rateday by day. These are numerous applicationday by day. These are numerous applicationof microprocessor. They are used in industryof microprocessor. They are used in industry,instrumentation, transportation, military,instrumentation, transportation, militaryequipment like tanks, radars etc. banks,equipment like tanks, radars etc. banks,business organizations, communication,business organizations, communication,automatic testing of products, lift control,automatic testing of products, lift control,

speed control of motors, automatic controlspeed control of motors, automatic controlof generators voltage, fuel control of of generators voltage, fuel control of furnaces consumers and commercialfurnaces consumers and commercialapplications etc.applications etc.



1717

17321411 microprocessor 8085 by shaheen fatima

Documents