تهيه كننده: علي برادران هاشمي

گارگاه کامپیوتر

CPU and Main Memory

2

The CPU is the main chip in the computer Brain of the PC The CPU is also called the microprocessor The most important chip in the computer

Modern processors contain millions of transistors which are etched onto a tiny square silicon called a die, which is about the with of a standard thumb.

The CPU processes instructions, performs calculations, and manages the flow of information through a computer

The CPU performs millions of calculations every second

Central Processing Unit (CPU)

3

CPU (Cont.)

InputDevice

OutputDevice

Primary Memory

Second Memory

Input Processing Output

CPUCU ALU

CPU: Central Processing UnitALU: Arithmetic Logic Unit CU : Control Unit

4

Send signals to execute strored programs DOES NOT execute programs but tells other to

execute Primary functions :

1. Read & Interpret program instructions2. Direct operation of process3. Control memory access (Data In/Out)

Program is loaded in RAM. During the execution program instructions

moves to control unit.

Control Unit (CU)

5

Arithmetic Operations: Addition, subtraction, division, multipication

Logical operations : Equal, Greater than,…

ALU

6

How the CPU executes Program Instructions ?

main Memory

Control Unit Arithmetic/Logic Unit

Step 1 : Fetching

Step 2: Decoding Step 3: Executing

Step 4: Storing

Instruction Time Execution Time

7

8

Coprocessors take over calculations floating-point math.

Math coprocessors will speed your computer's operation when utilizing software applications that take advantage of its capabilities. Built-in in modern CPUs.

Math Coprocessor

9

INTEL 4004 - microprocessor introduced in 1970 with the speed of 108khz was the worlds first microprocessor.

INTEL 8080 running at the speed of 2 MHz was used in the

world's first PC, the Altair. INTEL 8086 1976 16-bit architecture that allowed it to work with

16-bit binary numbers and pass them through a 16-bit data bus.

The 8086 was available in clock speeds of 5Mhz, 8Mhz, and 10Mhz.

Processor History

10

INTEL 8088 1979 The 8088 was the first processor used in the

original IBM PC and XT personal computers. INTEL 80286 1982 286 processor. The 286 processor supported 16-bit

architecture, supported virtual memory, and was available in clock speeds of 8Mhz, 10Mhz, and 12Mhz.

Processor History(Cont.)

11

INTEL 80386DX 1985 The chip was available in clock speeds of

16mhz, 20mhz,  25mhz, and 33mhz. INTEL 80486DX 1989

The 486DX featured a built-in memory cache and 32-bit architecture. It had more than three times the computing power of the 386DX and was available in clock speeds of 25mhz, 33mhz, and 50mhz.

DX

12

INTEL 80386SX (1989) The 80386SX lacked a math coprocessor however

still featured the 32-bit architecture and built-in multitasking. The chip was available in clock speeds of 16mhz, 20mhz,  25mhz, and 33mhz.

INTEL 80486SX (1991) less expensive version of the 80486DX. It lacked the math coprocessor of the 80486DX

and ran at lower clock speeds then the DX it ran at 16mhz, 20mhz, 25mhz, or 33 MHz.

SX

13

INTEL 80486DX2 (march 2, 1992). Based upon the popular 486DX. Internal clock speeds that doubled that of

the system that operated it. A DX2 on a system with a 33mhz bus

would run at 66mhz. INTEL 80486DX4  (1993)

The 486DX4 would triple that of the system that operated it.

100 MHz.

Dx2 – Dx4

14

INTEL PENTIUM (march 22, 1993) designed to replace the 486 processors. The Pentium has a 32-bit address bus and a

64-bit data bus. It can operate at speeds of 60mhz to

200mhz. The Pentium was released in three

generations.

Pentium

15

The first-generation of Pentium processors was the Pentium 60 and 66 MHz.

The second-generation introduced march 7, 1994 included new processors from 75, 90, 100, 120, 133, 150, 166, and 200 MHz.

The third-generation of Pentium processors code named P55C were introduced January 1997,  which incorporated the new technology MMX.

The Pentium MMX processors were available 166, 200, 233 MHz, and 266 MHz mobile version.

Pentium Generations

16

INTEL PENTIUM PRO designed for the corporate users and for

high-end servers and workstations, preferably those using windows NT. 

The Pentium pro CPUs are extremely fast with 32-bit applications and 3-D image processing and rendering when compared to previous Intel processors.

The chip runs at 166mhz and higher

INTEL PENTIUM PRO!

17

INTEL PENTIUM II The Pentium II 233mhz was released in

1997 previous owners of Pentium motherboard

could not upgrade to this new type of chip unless the motherboard!?

they had included a SLOT 1 technology. The Pentium II runs from 233mhz to 450mhz.

P2

18

INTEL PENTIUM III (1999) The Pentium III chip continued to use

the SLOT 1 and could be used on previous Pentium II motherboards with BIOS support.

The Intel Pentium III chips have a ID for each chip helping to authenticate peoples purchase over the internet. Privacy

P3

19

Processors can be identified by two main parameters :

How wide they are and how fast they are.

The speed of a processor is fairly simple concept. Speed is counted in MegaHertz, which

means millions of cycles per second.

Processor Specifications

20

A little more complicated to discuss because there are three main

specifications in a process that are expressed in width: Internal registers. Data input and output bus. Memory address bus.

Processor Specifications

21

The size of the internal registers A register is a holding cell within the

processor; For example the processor can add

numbers in two different registers, storing the result in a third register.

The register size determines the size of the data the processor can operate on.

Internal Registers or Internal Data Bus

22

The address bus is the set of wires that carries the addressing information used to describe the memory location to which the data is being sent or from which the data is being retrieved.

As with the data bus, each wire in an address bus carries a single bit of information.

Address Bus

23

This single bit is a single digit in the address.

The more digits used in calculating these addresses, the greater the total number of address locations.

The size of the address bus indicates the maximum amount of RAM that a chip can address.

Address Bus

24

Process Memory-addressingProcessor Address Bus MB

8088/8086 20-bit 1

286/386SX 24-bit 16386DX/486/Pentium 32-bit 4,096

Pentium II, III, IV 36-bit 65,536

25

A small very fast memory. Holding recently accessed data,

designed to speed up subsequent access to the same data.

When data is read from, or written to, main memory a copy is also saved in the cache, along with the associated main memory address.

Cache memory

26

All modern processors starting with the 486 family include integrated L1 cache.

L1 cache is built in to the processor die, this means it runs at full core speed of the processor.

Main system RAM is often slower than the CPU so L1 cache works as a temporary storage space between the CPU and memory.

Internal Level 1 (L1) Cache

27

Think of L1 cache as local computer distributor. When a client (CPU) calls up and requires a

certain part for a computer, the distributor (L1) checks its inventory for that part.

If it has it in stock, it sends that part out right away and you get it very quickly. (Cache hit).

If that part is not in stock, it must call up its head office (RAM) and have them ship it, which takes much longer to receive. (Cache miss).

Ok… But What Does It Do?

28

When there is a cache miss, the processor must go to memory and read through it and locate the information. Main memory runs a lot slower then L1 cache. Because of this, it takes much longer to get the appropriate information.

L2 cache is an even larger storage space that gathers information from RAM incase there is a cache miss with the L1. This way we can speed up the process a little better.

Level 2 (L2) Cache

29

This of L2 cache as a Regional Office When the distributor (L1) does not have a

certain item in stock, instead of calling all the way to the head office (RAM), they call the regional office (L2) which is much closer.

If the regional office (L2) has the part, they can ship it out much fast than the head office.

If the regional office (L2) does not have this part, then the head office (RAM) must be called.

Ok… Again what does it do?

30

Depending on the type of processor you purchase will depict the type of motherboard you will buy.

Most computers up to the 3rd generation of Pentiums used socket technology.

When Pentium 2 CPUs arrived, slot 1 became the new style.

Socket VS Slot

31

Slot 1

32

In the late 1990's, Intel decided to abandon the Socket type CPU design and move to a edge connected, or slot form CPU.

This allows for a much larger CPU package, which usually includes tightly coupled cache to boost CPU performance.

Intel Pentium II was the first of these slot type CPUs, utilizing Slot 1,

However, in order to compete in lower cost, easier to manufacture systems, Intel returned to the Socket for with Socket 370, and both the Pentium III and Celeron are now available in Socket 370 form.

Slot 1

33

developed by Digital Equipment for their Alpha processor

supports the new AMD Athlon, at speeds from 500 MHz to 800 MHz.

support for the Athlon’s 266MHz front side bus (FSB) appeared in the Fall of 2000 when AMD introduces it's new chipsets that support DDR (Double Data Rate) SDRAM.

AMD is phasing out Slot A in favor of Socket A.

Slot A

34

Socket 7

35

The Intel Pentium CPU is a Socket 8 device

The Intel Pentium PRO CPU is a Socket 8 device

Pentium PCs can be loosely divided into families by their CPU socket.

The majority of Pentium motherboards is Socket 7, But some Pentium and other upgrade processors can be used

on motherboards equipped with Socket 3 (486 and OverDrive CPU's), Socket 4 (60 and 66MHz Intel Pentiums) or Socket 5 (some of the mid-range Pentiums).

Socket 7 and 8

36

Socket 370

In January 1999, Intel released a new socket for P6 class processors.

The new socket is called socket 370, because it has 370 pins and was designed for lower-cost PGA versions of the Celeron and the P3.

37

Intel has decided to take it's Celeron CPU back into competiton in the PGA (Pin Grid Array) Socket world, in parallel with continuing to produce it as a Slot 1 device. Socket 370, so named for it's 370 pin grid, is NOT

compatible with Socket 7 or Super 7, it just looks similar. The Pentium III is now also available for Socket 370, but

make sure your Socket 370 motherboard can handle a 100MHz or 133MHz bus before wasting a FCPGA (Flip Chip Pin Grid Array) Pentium III on it.

The Socket 370 motherboards don't carry external cache, the new Celeron for Socket 370 has 128KB on the die, the Pentium III for socket 370 has 256KB on-board.

Socket 370 (cont.)

38

Socket 423, named for its 423 pins, The original Pentium 4 socket. Socket 478 is the successor to 423,

supporting new sizes and speeds of the P4. current P4s only support Rambus RIMM

for high performance or the old PC133 memory for slower systems, support for 266MHz DDR is now.

The P4 is not available in a slot format.

Socket 423 and 478

39

AMD is currently the only manufacturer of Socket A CPUs, these being the Athlon and the Duron. Socket A CPUs are somewhat less

expensive than their Slot A brothers, due to the smaller package and reduced amount of cache memory integrated with the CPU.

AMD warns that Socket A CPUs should not be used with adapters as Slot A CPUs.

Socket A

40

Definitions of Memory Memory is the workspace of the computer’s

processor. A temporary storage space where the programs

and data being operated on must reside.

Memory refers to integrated circuits that store program instructions and data that can be retrieved.

Memory is the part of the computer that holds data and instructions for processing.

Names of Memory primary storage ,primary memory, main storage, internal

storage, main memory

Memory

41

Random Access Memory (RAM) Memory that provides temporary storage for data

and program instructions. The programs and data stored in RAM are erased

when the power to the computer is turned off.

Read Only Memory (ROM) Memory that can be read-only and that store data or

instructions that do not change. Data and instructions in it remains after the power is

turned off.

RAM and ROM - Memory (2)

42

Read Only Memory

This type of memory is Read Only meaning that it is almost impossible to write to it!

ROM is non volatile, meaning it does not require electricity for information to remain in ROM.

ROM

43

Programmable ROM Similar to ROM, except there is a fuse

connected to ground. Hence, the default value is 0. Burn the

fuse to get 1. It can only be write to once.

Firmware Instructions that are stored in ROM are

called firmware.

ROM (cont.)

44

Erasable PROM A special transistor instead of the fuse (as in PROM) is

used. It allows the stored data to be erased and

reprogrammed. EPROM uses ultraviolet light to erase the content.

EEPROM uses higher than normal electricity voltage to erase the content.

The number of times it can be reprogrammed is limited.

The speed of EEPROM is slower than RAM as it can only erase and reprogram one byte at a time.

ROM (cont.)

45

Flash memory is based on EEPROM technology. It uses normal voltage to erase and reprogram. Faster than EEPROM as it can erase and

reprogram one block of memory at a time (instead of one byte at a time).

Flash memory is used in digital cellular phones, PDAs, digital cameras, LAN switches, digital set-up boxes, embedded controllers, and other devices.

In modem PCs, flash memory is commonly used to store system BIOS.

Flash memory

46

Basic Input/Output System The BIOS is built-in software that determines

what a computer can do without accessing programs

from a disk. It tells the microprocessor what to do after

right after you turn on the computer. On PCs, the BIOS contains all the code required

to control the keyboard, display screen, disk drives, serial communications, and a number of miscellaneous functions.

BIOS

47

DRAM :Dynamic RAM) built from capacitors; it’s called dynamic because it must

periodically refresh the capacitors. higher density, lower speed used in main memory Refreshing the memory takes processor

time from other tasks. For each refresh cycle, there are multiple

processor cycles.

RAM

48

SDRAM: Synchronous Dynamic RAM

DDR SDRAM: Double Data Rate SDRAM

RDRAM: Rambus DRAM (proprietary) (DRDRAM)

49

SRAM: Static RAM because it does not require refreshing. Not only are refreshes not required, SRAM is much

faster then DRAM. SRAM is available in access times of 2ns or less,

which means it can keep pace with modern processors.

lower density, higher speed SRAM uses a cluster of six transistors for each bit of

storage. Problem with SRAM is it is very expensive. SRAM is mostly used in CACHE memory inside of

processors and on motherboards

SRAM

50

Extended Data Out RAM became available with Pentium systems in 1995.

Allowing the memory controller to begin a new instruction while it is currently reading data at that current address.

The actually use EDO memory, your motherboard chipset must support it.

EDO is great for systems with bus speeds of up to 66mhz, which fit perfectly with the PC market through 1997.

However, in 1998 EDO lost out to a newer fast memory called SDRAM.

EDO DRAM

51

Synchronous DRAM A type of DRAM that runs in synchronization with

the memory bus. SDRAM delivers information in very high-speed

bursts using a high-speed, clocked interface. SDRAM synchronizes with the motherboards clock

speed.

SDRAM is sold in DIMM form and is often rated by MHz speed rather than nanosecond cycling time.

SDRAM is sold as PC66, PC100, PC133.

SDRAM

52

Rambus DRAM (late 1999). Intel endorsed and supported RDRAM in most of the

new PC motherboard chipsets from 1999 and beyond. Conventional memory systems that use EDO or

SDRAM are know as wide channel systems. They have memory channels as wide as the

processor’s data bus, which for the Pentium is 64 bits.

The DIMM is a 64-bit wide device, meaning data can be transferred to it 64 bits or 8 bytes at a time.

The fastest DIMMs are the SDRAM type, which run at 133mhz, meaning the overall throughput is 100x8 = 800Mb/sec.

RDRAM

53

RDRAMs are a narrow channel devices. They transfer data only 16 bits at a time,

but at much faster speeds. They normally run 800Mhz, meaning the

overall throughput is 800 x 2 = 1.6GB per second.

Each individual chip is serially connected to the next on a package called a RIMM (Rambus inline memory module).

RDRAM (Cont.)

54

Double data rate (DDR) SDRAM Data is transferred twice as fast. Instead of doubling the actual clock rate, DDR

memory achieves the doubling in performance by transferring twice per transfer cycle, once at the leading and once at the trailing edge of the cycle.

DDR-SDRAM uses a new DIMM module design with 184 pins.

DDR DIMMs are rated for either PC200 (100mhz x 2) or PC266 (133mhz x 2) operation and normally run on 2.5 volts.

DDR SDRAM

55

Originally, memory was installed into computers via individual chips.

These chips were often called DIP (Dual Inline Package).

The original XT and AT had 36 sockets on the motherboard for these individual chips.

Because it was very time consuming and tedious to install, SIMMs and DIMMs became very popular

DIPs

56

Single Inline Memory Module. SIMMs are little circuit boards that have

memory chips soldered onto them. There are two main types of SIMMs.

30-pin (8 Bit) 72-pin (32 Bit)

30-pin SIMMs were smaller than the 72-pin SIMMs and often had chips on both sides.

SIMMs

57

The main problem with SIMMs was one 30-pin SIMM was only 8 bits and one 72-pin SIMM was only 32 bits.

In order for a computer to function, memory must have the same BUS width as the motherboard.

If a motherboard’s bus was 32 bits and the computer only supported 30-pin SIMMs, you needed to install the memory in groups of 4 to make a 32 bit memory bus.

If a motherboard’s bus was 64 bits and the computer supported 72-pin SIMMs, you needed to install the memory in groups of 2 to make a 64 bit memory bus.

Problem with SIMMs

58

Dual Inline Memory Module. DIMMs, which are more popular now are 168-pin

units with 64-bit data paths. You only have to install 1 DIMM into a computer for it to

work with the 64 bit data bus. To have a reliable system, you must install SIMMs

or DIMMs with gold plated contacts into gold-plated sockets and SIMMs or DIMMs with tin-plated contacts into tin-plated sockets.

If you don’t follow this rule, you will get memory errors! When tin and gold come into contact, because one surface is hard,

the oxidation builds up and does not break easily under pressure. This leads to interruptions in electrical signals between SIMM or

DIMM and the memory socket.

DIMMs

59

In communications, parity checking refers to the use of parity bits to check that data has been transmitted accurately.

The parity bit is added to every data unit (typically seven or eight bits ) that are transmitted.

The parity bit for each unit is set so that all bytes have either an odd number or an even number of set bits.

Parity?

60

Error Correcting Circuits, Error Correcting Code, or Error Correction Code not only detects both single-bit and multi-bit

errors, it will actually correct single-bit errors on the fly.

a step beyond simple parity checking. ECC memory.

specifically designed to allow the use of ECC on modern systems that have a chipset that supports it.

ECC

61

Real Mode Memory Model

62

It resides in the first 1 meg of memory DOS systems have an address space of 1MB

but the top 384K is reserved for system use. This leaves 640K of conventional memory

DOS -based systems, upper memory refers to the memory area between the first 640K and 1 megabyte

Expanded Memory Specification Expanded Memory Manager (EMM) EMM386.EXE driver which is included with MS-

DOS, Windows 3.1 and Windows 95 systems

Conventional memory

63

Imaging RAM When RAM is full!? Run no more program! Virtual memoy is a system software

addition to OS. Use secondary storage as Primary!

Virtual Memory

64

65

Registers RAM Internal clock (Hz) BUS

Path between component of a computer 16 bit,32 bit, 64 bit.

Factors affecting processing speed

66

ISA (Industry Standard Architecture) 16 bit

EISA (Extended ISA) 32bit

PCI (Peripheral Component Interconnect) 1992 33MHz , 32 bit 132 MB/s

BUS

67

Firewire (IEEE1394) 100,200,300,400 MB/s Digital camera, DV Camcorders

USB (Universal Serial Bus) 12MB/s Plug & Play

BUS (Cont.)

68

Any Question?Any Question?