80486 Block Diagram

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80486, 80486 datasheet pdf, 80486 data sheet, Datasheet4U.com. Explain the architecture of Intel 80486 the help of a block diagram? Explain the similarities diff b/w 80386 and 80486? With neat block diagram explain the BIU unit of 80386? List out the maskable and non maskable interrupts available in 80386?

Microprocessor Definition – What do you have knowledge about micro processor? May be you have but I ensure that you have not detail information about it, if you having then very well. Here we will fully explain about microprocessor. Microprocessor is a hardware component of computer, and it works as brain of the computer system as well as use in computer because without using microprocessor, Computer like as plastic box. Microprocessor shape as a small chip that is made by silicon and it has to responsible to all functions of central processing unit.

Microprocessor meaning is a control unit ofcomputerbecause it is able to manage all various Arithmetic Logical Unit (ALU) operations. Microprocessor can capable to execute other operations such as computational activities like as addition/subtraction, internal processing, device terminals communication, and I/O management.

Block Diagram of Microprocessor

Users can send input to microprocessor with the help of different types of input devices of computer such as mouse, keyboard, touchpad, and touch screen etc.

Microprocessor manipulates all calculation such as adding/subtracting with using ALU, control Unit, and Register Array. After executing the instructions store it into memory area, and finally send those output for displaying on the output devices such as computer monitor.

READ MORE – Motherboard and their Types & Function

History of Microprocessor – Here, we spread the light on brief history of microprocessor.

First microprocessor was developed by INTEL in 1971, and its name was Intel 4004. Intel 4004 is based on 4 bit processor; due to this it was not more popular. Intel 4004 was able to perform only addition/subtraction operation on 4 bit at once.

Intel was announced new Intel’s 8080 in 1974 for personal computer. It is based on 8 bit processor.

In 1976, Intel was designed 8085 processor but it was not new invention because 8085 microprocessor was updated version of 8080 microprocessor. In 8085 microprocessor, are attached two Enable/Disable Instructions, 3 interrupt pins and serial I/O pins.

In 1976, Intel was announced again new 8086 microprocessor. 8086 microprocessor is better to 8085 because it is based on 16 bit.

Given to all microprocessor were not supportable for Floating point instructions. Floating point means to decimal number such as (456.23).

Later, Intel was designed other new 8087 microprocessor that was first math co-processor, and this processor was embedded into IBM PC.

Due to more effort of microprocessor’s companies, other new processor are come in market such as 8088,80286,80386,80486,Pentium II, Pentium III, Pentium IV and now Core 2Duo,Dual Core and Quad core processors.

Evolution of Microprocessor

Here, we will discuss about short note on evolution of microprocessor, and further Microprocessor evolution is divided into five generation, and every generation are described below.
First Generation:

First generation of microprocessor was introduced by Intel from 1971 – 1972.Those types of microprocessors are capable only to processed in serially of all instructions. They have been done their process cycle in three steps like as fetched, decoded and then executed. When microprocessor completed cycle then to be update the instruction pointer, and these operations are performed consecutive for every instructions.

Examples are:

  • INTEL 4004 Rockwell
  • PPS-4 INTEL 8008

Second Generation:

Diagram

Second generation microprocessor was designed in 1973-1978 with 8 bit processor. In those microprocessors, used various transistors on the integrated circuit. There are three steps for processing the instructions like as overlapped fetch, decode and execute. Due to this, second generation microprocessor is five time increase to first generation in different area like as in instruction, speed, execution and higher chip densities.

Examples are:

  • MC68000 Motorola microprocessor
  • Intel 8080
  • INTEL 8085
  • Motorola 6800 and 6801

Third Generation:

Third generation microprocessor was developed in 1978 along with 16 bit processor. This processor is more useful for minicomputer. Third generation microprocessor is used the HMOS technology and implement RISC-based architectures.

Examples are:

  • MC68020
  • Intel’s 8086
  • Zilog Z8000

Four Generation:

Four generation microprocessor was introduced from 1981 to 1995 with 32 bit processor. This microprocessor is designed with million transistors, and also based on HMOS technology. Those types of microprocessor are able to process couples of instruction in per clock cycle.

Examples are:

  • Motorola’s 88100
  • Intel’s 80960CA
  • INTEL 80386
  • Mororola 68020

Fifth Generation:

Fifth generation microprocessor had been come from 1995 along with 64 bit processor. In this microprocessor, have been embedded 10 million transistors. Due to this PCs are a low-margin, high-volume-business dominated by a single microprocessor.

Examples are:

  • PENTIUM
  • Celeron
  • Dual, quad and octa core processors

READ MORE –Computer Memory with Primary & Secondary

There are numerous different types of microprocessor those are used in the computer and their examples as well.

  • SIMD
  • Symbolic Processors
  • Bit-Slice Processors
  • Transputers
  • Graphic Processors

RISC (Reduced Instruction Set Computer):

RISC means to “Reduced Instruction Set Computer”. Main objective of designing RISC is to decrease execution time that is simplified by the computer’s instructions. RISC has to use just one clock cycle for producing the result on uniform execution time. RISC needs more couples of RAM memory to save all instructions, due to this reason decrease the efficiency for all codes which are used in the lines form.

Examples are:

  • DEC’s Alpha 21064, 21164 and 21264 processors
  • SUN’s SPARC and ULTRA SPARC;
  • PowerPC processors 601, 604, and more
  • MIPS: TS (R10000) RISC Processor
  • PA-RISC: HP 7100LC

CISC (Reduced Instruction Set Computer):

CISC stands for “Complex Instruction Set Microprocessors”. CISC has to contain the complex instructions set, and due to that reason CISC take couple to time for executing all instructions, hence its speed more slow to RISC. Main goal of CISC is developed for various activities such as download, upload, and swap data between the memory card and other devices which are connected with computer.

Examples are:

  • IBM 370/168
  • VAX 11/780
  • Intel 386, 486, 80486
  • Pentium Pro, Pentium, Pentium II, Pentium III, Pentium 4;
  • Motorola’s 68000, 68020, 68030, 68040

Superscalar Microprocessors:

Superscalar Microprocessor is able to execute huge tasks at a one time without delay because it has to contain the multiple pipelines structure. Mainly, this microprocessor is designed for the ALU or other types of multipliers as well.

Examples are:

  • Pentium, Pentium Pro
  • Pentium II, Pentium III

ASIC (Application Specific Integrated Circuit):

Stands for “Application Specific Integrated Circuit”. ASIC microprocessor is not designed for generic purpose because its motive of developing is to specific points such as automotive emissions control or personal digital assistants computer.

(DSP) Digital Signal Multiprocessors:

80486

DSP is also known as “Digital Signal Multiprocessors”. DSP processor helps to encode/decode the streaming videos as well as transform the digital signals to analog signals & analog signals to digital signals.DSP has superb power to calculate the mathematically instructions.

Examples are:

  • Texas instruments’ TMS 320C25,
  • Motorola 56000,
  • National LM 32900,
  • Fujitsu MBB 8764

Applications areas:

  • RADAR
  • Home Theaters
  • SONAR
  • Audio gears
  • TV set top boxes
  • Mobile phones

SIMD Processors:

SIMD (Single Instruction Multiple Data) is also known as “Array processor”. Prime objective of introducing the SIMD processor is to implement all computations into vector form. In SIMD, uses various processing elements in parallel form instead of serially. In that architecture, every processor elements have to use couples of ALUs, and every ALU contains their local memory for storing computational data.

Symbolic Processors:

Symbolic processor is also known as “LISP processors or PROLOG processors“. Symbolic processors are introduced for using in different fields such as expert system, machine intelligence, artificial intelligence, and pattern-recognition. In Symbolic processor, not need the floating point operations.

Bit-Slice Processors:

Bit-Slice processor is also known as building block because all microprocessors are designed for specific word length along with building blocks. Building block has to contain the 4-bit ALUs, micro programs sequencers, and carry look-ahead generators.

Examples are –

  • AMD-2900, 2909, 2910, 29300 series,
  • Texas instrument’s SN-74AS88XX series

Transputers:

Transputer microprocessor was developed in 1980 as a special type processor for managing to all component processor, and it includes various internal components such as FPU, Chip RAM and serial links, communication links etc. Communications links was helped to make connection between all transputers.

Examples are:

  • INMOS T414
  • INMOS T800

Graphic Processors:

80486 Block Diagram

Intel has been introduced graphic chip and assigned to name 740-3D. With using those processors, users can use high definition games and movies.

Examples are:

  • Intel 82786
  • Intel i860
  • Intel i750

READ MORE – Computer Monitor with its Types & Function

Here, we will discuss about various applications of microprocessor where different uses of microprocessor. Such as

General Purpose:

Use as Single board Micro Computers:

Microprocessors are used in the “Single board Micro Computers”, and in which has to use low configuration with software and hardware. It includes for designing small types of computers, and it useful for providing the training to students as well.

Embedded in PC:

In PC, it has been used two types of microprocessor such as 8 bit microprocessor or 16 bit microprocessor. 8 bit microprocessor is more suitable for playing games and using short term programs, and 16 bit microprocessor is helpful for word processing, payroll, business accounts.

Include in Super Minis and CAD:

In Super Minis and CAD, has to use of 32 bit microprocessor because its performance is superb compare to mainframe and mini-computers.

Specific Purpose:

Instrumentation:

Microprocessor has a intelligent devices with accepting programmability. It uses in various medical instruments as a controller such as to determine blood pressure and temperature.

Controller:

Microprocessors are included in various appliances which are used in home such as microwave oven, washing machine, coffee makers, radio clocks, toasters, televisions, VCRs, DVD players, ovens, stoves, clothes washers, stereo systems. In industry, it uses for measure various metric such as speed, temperature, moisture and pressure, and suitable transduction.

Other home equipments are included microprocessor such as bread machines, dishwashers, home lighting systems and some refrigerators.

Communication Sector:

In the telecom sector, microprocessor is used in the digital telephone system, telephone exchange and modem as well. Microprocessor play vital role in the railway reservation system and airlines reservation system at international level. Other areas such as Satellite communication systems, mobile phones, televisions and LAN / MAN network with computer network as well.

Use as an Office Automation and Publication:

Microprocessor has low cost and user friendly, due to those reasons it uses in various parts in office such as word processing, spreadsheet operations, storage and retrieval of huge information. In publication, microprocessor has to use in various areas like as automatic photo copies, LASER printers for getting better quality as well as good speed.

Uses for Consumers:

Today, microprocessor is used as consumer for different areas such as making toys, amusement devices, and embedded in house held devices with more entertainment and full pack stunning features as well.

Other application segments are:

  • Calculator machine
  • Accounting computation system
  • Games devices
  • Traffic light controlling system
  • Complicated Industrial Controller terminals
  • Helping to create multiuser and multi function environment
  • Military areas
  • Broadcasting system
  • Data acquisition systems

In this section, we solve your doubt that how does a microprocessor work? as well as explain numerous microprocessor functions.

  • It controls of all components of machine and broadcast the timing signals.
  • Microprocessor retrieves all instructions from main memory such as RAM and ROM.
  • These fetched data are decoded, and decide which operation is to be performed as per condition.
  • All instructions are proceed for executing, and apply the arithmetically and logically operations according to situation.
  • It stores the executed programs.
  • Make the communication between all I/O devices, and transfer entire data.
  • If, it need extra execution of instructions then CPU help to supervision for all I/O devices.
  • In the end, finally outputs after execution of instructions send to memory or I/O Module.

There are various featuresand benefits of microprocessor. Describe below

  • Microprocessor helps to perform all complex arithmetically and logically instructions.
  • Microprocessor has more power to execute 3-4 billion instructions in one second, and it measure in Hertz.

80486 Block Diagram Block

Block
  • Microprocessor is able to transfer huge data one memory location to other location.
  • Microprocessor can be performed floating point number in few milliseconds.
  • Microprocessor is generic product, means it can be used in various electronic processing devices with pre-programmed for performing to specific task.
  • Microprocessor helps to provide accessibility for controlling of couple of equipments with in time sharing.
  • Microprocessor is able to multiprocessing and Parallel Processing.
  • Easy to modification.
  • Low cost.
  • Better Reliability and Versatility
  • Microprocessor needs to external controllers for performing huge tasks along with extra capability.
  • Microprocessor has flexible to program in nature.
  • Microprocessor is based on the Low Thermal Design Power (TDP) means to it enables to thinner, lighter, portable notebook devices.
  • Microprocessor has to include the “Hyper Threading”.

Microprocessor has various limitations (cons) over their advantages as well.

  • Microprocessors are getting more heat due to perform task.
  • In Microprocessor, small packet of data can be transfer.
  • Microprocessor does not contain any internal physical memory such as RAM or ROM.
  • It must not contact any external peripheral due to generate more heat.
  • Microprocessor is totally base on the machine language.
  • Degrade to 3D performance.

8259 microprocessor is defined as Programmable Interrupt Controller (PIC) microprocessor. There are 5 hardware interrupts and 2 hardware interrupts in 8085 and 8086 respectively. But by connecting 8259 with CPU, we can increase the interrupt handling capability. 8259 combines the multi interrupt input sources into a single interrupt output. Interfacing of single PIC provides 8 interrupts inputs from IR0-IR7.

For example, Interfacing of 8085 and 8259 increases the interrupt handling capability of 8085 microprocessor from 5 to 8 interrupt levels.

Features of 8259 PIC microprocessor –

  1. Intel 8259 is designed for Intel 8085 and Intel 8086 microprocessor.
  2. It can be programmed either in level triggered or in edge triggered interrupt level.
  3. We can masked individual bits of interrupt request register.
  4. We can increase interrupt handling capability upto 64 interrupt level by cascading further 8259 PIC.
  5. Clock cycle is not required.

Pin Diagram of 8259 –


We can see through above diagram that there are total 28 pins in 8259 PIC microprocessor where Vcc :5V Power supply and Gnd: ground. Other pins use are explained below.

Block Diagram of 8259 PIC microprocessor –

The Block Diagram consists of 8 blocks which are – Data Bus Buffer, Read/Write Logic, Cascade Buffer Comparator, Control Logic, Priority Resolver and 3 registers- ISR, IRR, IMR.

  1. Data bus buffer –
    This Block is used as a mediator between 8259 and 8085/8086 microprocessor by acting as a buffer. It takes the control word from the 8085 (let say) microprocessor and transfer it to the control logic of 8259 microprocessor. Also, after selection of Interrupt by 8259 microprocessor, it transfer the opcode of the selected Interrupt and address of the Interrupt service sub routine to the other connected microprocessor. The data bus buffer consists of 8 bits represented as D0-D7 in the block diagram. Thus, shows that a maximum of 8 bits data can be transferred at a time.
  2. Read/Write logic –
    This block works only when the value of pin CS is low (as this pin is active low). This block is responsible for the flow of data depending upon the inputs of RD and WR. These two pins are active low pins used for read and write operations.
  3. Control logic –
    It is the centre of the microprocessor and controls the functioning of every block. It has pin INTR which is connected with other microprocessor for taking interrupt request and pin INT for giving the output. If 8259 is enabled, and the other microprocessor Interrupt flag is high then this causes the value of the output INT pin high and in this way 8259 responds to the request made by other microprocessor.
  4. Interrupt request register (IRR) –
    It stores all the interrupt level which are requesting for Interrupt services.
  5. Interrupt service register (ISR) –
    It stores the interrupt level which are currently being executed.
  6. Interrupt mask register (IMR) –
    It stores the interrupt level which have to be masked by storing the masking bits of the interrupt level.
  7. Priority resolver –
    It examines all the three registers and set the priority of interrupts and according to the priority of the interrupts, interrupt with highest priority is set in ISR register. Also, it reset the interrupt level which is already been serviced in IRR.
  8. Cascade buffer –
    To increase the Interrupt handling capability, we can further cascade more number of pins by using cascade buffer. So, during increment of interrupt capability, CSA lines are used to control multiple interrupt structure.

SP/EN (Slave program/Enable buffer) pin is when set to high, works in master mode else in slave mode. In Non Buffered mode, SP/EN pin is used to specify whether 8259 work as master or slave and in Buffered mode, SP/EN pin is used as an output to enable data bus.

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80486 Pin Diagram






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