ProcessorProcessorWriter:-Rashedul HasanWriter:-Rashedul Hasan

Editor:- Jasim UddinEditor:- Jasim Uddin

ProcessorProcessor

When entire CPU (both CU & ALU) is contained When entire CPU (both CU & ALU) is contained on a single tiny silicon chip, it is called on a single tiny silicon chip, it is called microprocessor. microprocessor.

Silicon is an element that is widely found in clay Silicon is an element that is widely found in clay and sand. It is a semiconductor. and sand. It is a semiconductor.

Semiconductor is material whose electrical Semiconductor is material whose electrical properties are intermediate between a good properties are intermediate between a good conductor of electricity and nonconductor of conductor of electricity and nonconductor of electricity.electricity.

Example of Conductor & Example of Conductor & NonconductorNonconductor

An example of good conductor of An example of good conductor of electricity is copper in household wiring.electricity is copper in household wiring.

An example of non conductor of electricity An example of non conductor of electricity is the plastic sheath around the wiring. is the plastic sheath around the wiring.

MicroprocessorMicroprocessor

chip inside Pentium 4 processorchip inside Pentium 4 processor

Inside the Microprocessor Inside the Microprocessor

Arithmetic Logic UnitArithmetic Logic Unit Control UnitControl Unit Registers Registers

RegistersRegisters

ALU contain registers. Therefore Register ALU contain registers. Therefore Register is a part of CPU not main memory. is a part of CPU not main memory.

Register is high speed storage area used Register is high speed storage area used to speed up the processing. to speed up the processing.

The length of a register equals the number The length of a register equals the number of bits it can store. For example, if a of bits it can store. For example, if a register can store 8 bits, will be referred to register can store 8 bits, will be referred to 8 bit register.8 bit register.

RegistersRegisters

Most CPU sold today have 64 bit register. Most CPU sold today have 64 bit register. It is also called Word size.It is also called Word size. The bigger the word size, the faster the The bigger the word size, the faster the

computer can process the data. computer can process the data.

Common Registers.Common Registers.

Although the number of registers varies Although the number of registers varies from computer to computer, there are from computer to computer, there are some registers common to all computer. some registers common to all computer. They are listed bellow,They are listed bellow,

Memory address Register [MAR]: Holds Memory address Register [MAR]: Holds address of the active memory location.address of the active memory location.

Memory Buffer Register [MBR]: Holds Memory Buffer Register [MBR]: Holds information on its way to and from information on its way to and from memory.memory.

Common Registers.Common Registers.

Program Control Register [PC] : Holds Program Control Register [PC] : Holds address of the next instruction to be address of the next instruction to be executed. executed.

Accumulator Register [A] : Accumulates Accumulator Register [A] : Accumulates results and data to be operated upon.results and data to be operated upon.

Instruction Register [I] : holds an Instruction Register [I] : holds an instruction while it is being executed.instruction while it is being executed.

Input/Output Register [I/O] : Communicate Input/Output Register [I/O] : Communicate with Input & Output Devices. with Input & Output Devices.

System clock rateSystem clock rate

Processor Speed. Processor Speed.

Processor performs at incredible speed. Processor performs at incredible speed. Every processor contains a system clock which Every processor contains a system clock which

control how fast the operations within a control how fast the operations within a computer take place. computer take place.

Instruction are fetched, decoded and executed Instruction are fetched, decoded and executed at proper intervals with intervals timed by a at proper intervals with intervals timed by a specific number of clock cycle.specific number of clock cycle.

The The clock rateclock rate is the fundamental rate in is the fundamental rate in cycles cycles per secondper second (measured in hertz) at which a (measured in hertz) at which a computer performs its most basic operations computer performs its most basic operations such as adding two numbers or transferring a such as adding two numbers or transferring a value from one register to another. value from one register to another.

Clock CycleClock Cycle

One clock cycle is the time it takes to perform One clock cycle is the time it takes to perform one operation such as moving a byte of data one operation such as moving a byte of data from one memory location to another. from one memory location to another.

Normally several clock cycles are required to Normally several clock cycles are required to fetched, decoded and executed a single fetched, decoded and executed a single program instruction. program instruction.

Shorter the clock cycle, faster the processor. Shorter the clock cycle, faster the processor. A single clock cycle typically lasting only a few A single clock cycle typically lasting only a few

nanoseconds in modern microprocessors nanoseconds in modern microprocessors

Ways of measuring processing Ways of measuring processing speed. speed.

Faster clock speeds will result in faster Faster clock speeds will result in faster processing. processing.

For microcomputer–Megahertz & Gigahertz For microcomputer–Megahertz & Gigahertz Megahertz: a measure of frequency Megahertz: a measure of frequency equivalent to 1 million cycle [approx] per equivalent to 1 million cycle [approx] per second. second. for example, 933-MHz Pentium 3 processor for example, 933-MHz Pentium 3 processor can process 933 million cycles per second. can process 933 million cycles per second.

Ways of measuring processing Ways of measuring processing speed.speed.

Gigahertz: a billion cycles per second. Gigahertz: a billion cycles per second. For minicomputers & Mainframes-MIPS:For minicomputers & Mainframes-MIPS:

MIPS stands for million of instruction per MIPS stands for million of instruction per second.second.a mainframe can perform at 200-1200 MIPSa mainframe can perform at 200-1200 MIPS

For Supercomputer-Flops: For Supercomputer-Flops: Flops stands for Floating point operations per Flops stands for Floating point operations per second. A Floating point operation is special second. A Floating point operation is special kind of mathematical calculation. kind of mathematical calculation. in case of super computer it is expressed as in case of super computer it is expressed as Megaflops, Gigaflops & Teraflops. Megaflops, Gigaflops & Teraflops.

Processor Speed affected by:Processor Speed affected by:

System clock rateSystem clock rate = Rate of an electronic pulse = Rate of an electronic pulse used to synchronize processing.used to synchronize processing.(Only one action can take place between (Only one action can take place between pulses.) pulses.)

Measured in Measured in megahertzmegahertz ( (MHzMHz) where 1 MHz = ) where 1 MHz = 1 million cycles per second or1 million cycles per second or gigahertz gigahertz ( (GHzGHz) ) where 1 GHz = 1 billion cycles per second.where 1 GHz = 1 billion cycles per second.

This is what they are talking about if they say a This is what they are talking about if they say a computer is a 2.4 GHz machine. It's clock rate is computer is a 2.4 GHz machine. It's clock rate is 2.4 billion cycles per second. 2.4 billion cycles per second.

Bigger number = faster processingBigger number = faster processing

Architecture & Design of processorArchitecture & Design of processor

Two main architecture or design for Two main architecture or design for microprocessor are, microprocessor are,

CISC : Complex Instruction Set Computing CISC : Complex Instruction Set Computing chips, which are used mostly in PCs, can chips, which are used mostly in PCs, can support a large number of instruction but support a large number of instruction but at relatively low processing speed. at relatively low processing speed.

Architecture & Design of processorArchitecture & Design of processor

RISC : Reduced Instruction Set Computing chips, mainly RISC : Reduced Instruction Set Computing chips, mainly used mostly in workstation. used mostly in workstation.

Multi-core designs:Multi-core designs:A different approach to improving a computer's A different approach to improving a computer's performance is to add extra processors. A multi-core performance is to add extra processors. A multi-core processor is simply a single chip containing more than processor is simply a single chip containing more than one microprocessor core, effectively multiplying the one microprocessor core, effectively multiplying the potential performance with the number of cores. potential performance with the number of cores. From 2007 dual-core processors are widely used in From 2007 dual-core processors are widely used in servers, workstations and PCs while quad-core servers, workstations and PCs while quad-core processors are now available for high-end applications in processors are now available for high-end applications in both the home and professional environments. both the home and professional environments.

AMD Athlon Dual core processor AMD Athlon Dual core processor

Kinds of Processor.Kinds of Processor.

Intel type chips : For PCIntel type chips : For PC About 90% of microprocessor use Intel About 90% of microprocessor use Intel

type microprocessor. type microprocessor. Are mainly made by the Intel Corporation.Are mainly made by the Intel Corporation. Other manufacturers of this type includes, Other manufacturers of this type includes,

AMDAMD CyrixCyrix DECDEC

Kinds of Processor.Kinds of Processor.

Motorola-Type chips : For MacintoshesMotorola-Type chips : For Macintoshes It is mainly made by Motorola for Apple It is mainly made by Motorola for Apple

Macintoshes computer. Macintoshes computer.

Bus SpeedBus Speed

Are data road ways through which bits are transmitted within the CPU an between CPU and other

components of motherboard.

Bus SpeedBus Speed

Bus SpeedBus Speed = the amount of data the CPU can = the amount of data the CPU can transmittransmit at a time to main memory and to input at a time to main memory and to input and output devices. and output devices. (Any path bits travel is a (Any path bits travel is a busbus.) .)

An 8-bit bus moves 8 bits of data at a time. An 8-bit bus moves 8 bits of data at a time. Bus width can be 8, 16, 32, 64, or 128 so far. Bus width can be 8, 16, 32, 64, or 128 so far.

Think of it as "How many passengers (bits) can Think of it as "How many passengers (bits) can fit on the bus at once to go from one part of the fit on the bus at once to go from one part of the computer to another." computer to another."

Bigger number = faster transfer of dataBigger number = faster transfer of data

Important Things to KnowImportant Things to Know

You want a nice match between the word size You want a nice match between the word size and the bus size and the clock. It wouldn't do and the bus size and the clock. It wouldn't do any good to have a bus that can deliver data any good to have a bus that can deliver data 128 bits at a time, if the CPU can only use 8 bits 128 bits at a time, if the CPU can only use 8 bits at a time and has a slow clock speed. A huge at a time and has a slow clock speed. A huge line of data would form, waiting to get off the line of data would form, waiting to get off the bus! When computers gets clogged like that, bus! When computers gets clogged like that, bad things can happen to your data. It's like bad things can happen to your data. It's like people waiting to get into the theater. After a people waiting to get into the theater. After a while, some of them may leave!! while, some of them may leave!!

Types of BUSTypes of BUS

Parallel Bus Parallel Bus

Serial BusSerial Bus

Parallel & Serial BusParallel & Serial Bus

Buses can be parallel buses, which carry Buses can be parallel buses, which carry data words in parallel on multiple wires, data words in parallel on multiple wires,

or serial buses, which carry data in bit-or serial buses, which carry data in bit-serial form. serial form.