Transcript Prezentace
Department of Computer Science Faculty of Civil Engineering, Brno University of Technology Information Technology 1 1
Inside the Personal Computer
Repetition
• A computer is a data processing machine which is operated automatically under the control of a list of instructions (called a program) stored in its main memory.
• Conventional digital computers have a common form that is attributed to von Neumann .
• Von Neumann computers are general purpose computers . • Data and instructions are both stored in the main memory.
• Central processing unit ( CPU , processor ) contains the control unit that coordinates the execution of instructions, and the arithmetic-logic unit that performs arithmetic and logic operations.
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Repetition
Control unit Arithmetic-logic unit Registers Instructions Data Main memory (operational) CPU 3
Repetition
• The main (operational) memory is used to store program and data which are currently manipulated by the CPU. Main memory is fast and of limited size.
• The peripheral (secondary) memory provides the long-term storage of large amounts of data and program. It is relatively slow and of very large size.
• The most important characteristics of a memory are speed ( access time and data transfer rate ), size and cost , which are mainly constrained by the technology used for its implementation.
• Facts : • The faster memory is, the greater the cost/bit is.
• (The larger memory is, the slower is it.) 4
The Anatomy of a PC
– Key Concepts
RAM
An acronym for memory that R andom A ccess M emory. It is random because any of the bits or bytes resident in RAM can be accessed nonseqeuntially. RAM is can be both read and written to . The information stored in a semiconductor RAM will be lost when electrical power is removed .
ROM
An acronym for R ead O nly M emory. We cannot write new data to those memories.
several subtypes of ROM: “classical” PROM EPROM There are ROM , (Programmable ROM), EEPROM (Erasable PROM), (Electrically EPROM), Flash-EEPROM .
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The Anatomy of a PC
– Key Concepts
BIOS
An acronym for B asic I nput/ chip on the motherboard.
O utput S ytem. A collection of software codes built into a PC. BIOS is stored in ROM (Flash-EEPROM usually)
Boot
The process that takes place when a PC is turned on and it performs the routines necessary to get all the components functioning properly and then load the operating system .
POST
An acronym for functioning.
P ower O n S elf T est, a procedure the computer goes through when booting to verify that the basic components of a PC are 6
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The Anatomy of a PC
– Key Concepts
CMOS
An acronym for C omplementary M etal O xide S emiconductor – a term that describes how a CMOS chip is manufactured. Powered by a small battery, the CMOS memory chip retains crucial information about what hardware a PC comprises even when the power is turned off.
Clock
A microchip that regulates the timing and speed of all the computer’s functions. The chip includes a crystal that vibrates at a certain frequency when electricity is applied to it. The speed of clocks – – and therefore computers – is expressed in megahertz (MHz) or gigahertz (GHz). Thus a PC may be desribed as having a 1.2 GHz processor, which means that the processor has been designed to work with a clock chip runnig at that speed.
Types of RAM
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DRAM
( D ynamic R andom A ccess M emory) For years, the most common type of main RAM.
“Dynamic” refers to the memory's method of storage – basically storing the charge on a capacitor, which leaks the charge over time and must be refreshed about every thousandth of a second.
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SRAM
( S tatic R andom A ccess M emory) RAM that, unlike DRAM, doesn't need to have its electrical charges constantly refreshed. SRAM is usually faster than DRAM but more expensive.
Memory Modules
Memory module is a small circuit board with the memory chips (RAM). It uses less board space and it is more compact.
• • •
SIMM DIMM
( S ingle I n-Line M emory M odule) 30- or 72-pin ( D ual I n-Line M emory M odule)
RIMM
( R ambus I n-Line M emory M odule) 9
Memory Modules
– cont‘d
SIMM (72-pin) 10 DIMM
Cache Memory
• The speed of the main memory is relative slow with respect to the today's processors.
• A cache memory is a small, retains copies of recently used information from the main memory. very fast memory that • Memory caching is effective because the running programs access the same data or instructions over and over.
• Cache capacity is much smaller than main memory (about 1/128 – 1/32 of the main memory capacity).
• Cache memory operates transparently to the programmer, automatically deciding which values to keep and which values to overwrite.
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Cache Memory
– cont‘d
• •
Primary cache
limited in size. (Level 1, L1 cache) is built into the processor chip with a zero wait-state (delay) interface to the processor's execution unit, it is
Secondary cache
(Level 2, L2 on the motherboard. cache) can be found 12
CPU (processor, microprocessor)
• CPU – C entral P rocessing U nit • often called the brains of a computer • CPU is a tight, complex collection of transistors arranged so that they can be used to manipulate data • most operations of the computer are handled by the processor • processor manufacturers: Intel, AMD, Cyrix 13
CPU
– cont'd
According to Moore's Law formulated in 1965 by Gordon Moore (co-founder of Intel), the number of transistors per integrated circuit would double every 18 months. Moore predicted that this trend would hold for the next ten years. In fact, as the graph illustrates, Intel has managed to doggedly follow this law for far longer. In 1978 the 8086 ran at 4.77 MHz and had less than 30,000 transistors. By the end of the millennium the Pentium 4 had a staggering 42 million on-chip transistors and ran at 1.5 GHz.
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CPU
– cont'd
15 Source: www.pctechguide.com
Processor Registers
• Registers are very fast temporary storage devices typically used to hold intensively used data and intermediate results.
• The set of registers within the CPU represents the top level of the memory hierarchy.
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User Visible Registers
• Can be accessed by programmers.
• They are often called general-purpose registers.
Control and Status Registers
• Used by the control unit to control the operation of the CPU; not directly accessible by the programmer.
Stack
• A list of data elements, with the restriction that elements can be added or removed at one end of the list only. This end is called the top of the stack and the other end is called the bottom .
• Placing a new element on top of the stack is an operation called push ; removing the top element is called pop .
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LIFO
– L ast I n F irst O ut 17 5 4 3 2 1 5 4 3 2 1
„Generations of Processors“
Type/Generation 8086
/First
8088
/First
80286
/Second
80386DX
/Third
80386SX
/Third
80486DX
/Fourth
80486SX
/Fourth
80486DX2
/Fourth
80486DX4
/Fourth
Pentium
/Fifth
Pentium MMX
/Fifth
Pentium Pro
/Sixth
Pentium II
/Sixth
Pentium II
/Sixth
Pentium III
/Sixth
AMD Athlon
/Seventh
Pentium 4
/Seventh 18
Year
1978 1979 1982 1985 1988 1989 1989 1992 1994 1993 1997 1995 1997 1998 1999 1999 2000
Data/ L1 Memory Internal Address Cache Bus [KB] Speed [MHz] Clock [MHz]
16/20 bit 8/20 bit 16/24 bit 32/32 bit 16/32 bit None None None None 8 4.77-8 4.77-8 6-20 16-33 16-33 4.77-8 4.77-8 6-20 16-33 16-33 32/32 bit 32/32 bit 32/32 bit 32/32 bit 64/32 bit 64/32 bit 64/36 bit 64/36 bit 64/36 bit 64/36 bit 64/36 bit 64/36 bit 8 8 8 8+8 8+8 16+16 8+8 16+16 16+16 16+16 64+64 12+8 25-50 25-50 25-40 25-40 60-66 25-50 25-50 50-80 75-120 60-200 66 66 66 166-233 150-200 233-300 66/100 100 300-450 450-600 100-200+ 500-600+ 100 1.4 – 2 GHz
Block Diagram of the 8086 Processor
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AMD Processors Athlon
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Duron K6-2
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Motherboard (mainboard)
The main circuit board inside the PC which holds • processor, • main (operational) memory – RAM, • CMOS memory (it is used to store basic information about the PC's configuration) • BIOS stored in ROM (usually Flash-EEPROM) • integrated floppy drive and hard drive controller • expansion slots (ISA, PCI, AGP, ...) • I/O ports and other interfaces (parallel and serial port, USB, …) • connectors to connect other parts of a computer (keyboard, small speaker, reset switch, power LED, CPU fan, …) ...
The above-stated information is dependent on the type of motherboard.
Motherboard (mainboard)
– cont'd
Graphics card, soundcard, faxmodem, etc. can be integrated on the motherboard (“All-In-One” motherboard).
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Expansion (I/O) Buses
• peripherals are connected to the I/O buses in various ways, primarily through connectors directly on the motherboard and through different interfaces such as expansion cards • I/O bus depends on the type of processor • slots (connectors of I/O bus) are placed on the motherboard • different types of I/O buses: ISA , MCA, EISA, VL-Bus, PCI , AGP 23
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ISA Expansion Bus
ISA
– I ndustry S tandard A rchitecture (also AT-Bus ) • the oldest, slowest and soon to become obsolete I/O bus • designed for 80286 processor • specifies a 16-bit transfer driven by a 8 MHz clock • It has a theoretical data transfer rate of up to 16 MBps. Functionally, this rate would reduce by a half to 8 MBps since one bus cycle is required for addressing and a further bus cycle for the 16-bits of data. In the real world it is capable of more like 5 MBps - still sufficient for many peripherals - and the huge number of ISA expansion cards ensured its continued presence into the late 1990s.
Block Diagram of the ISA Architecture
25 (simplified) ISA Bus Processor ISA controller Main memory L2 cache
PCI Expansion Bus
PCI
– P eripheral C omponent I nterconnect • designed for 80486 a Pentium processors • in its original implementation PCI ran at 33 MHz, it was later raised to 66 MHz • theoretical throughput to 266 MBps (33 times faster then ISA) • it can be configured both as a 32-bit and a 64-bit bus • supports the PnP standard (Plug and Play) 26
Block Diagram of the PCI Architecture
27 (simplified) ISA Bus PCI/ISA Bridge Processor PCI bus CPU/PCI Bridge Main memory L2 cache
PCI Slots
ISA Slots
28 Source: www.howstuffworks.com
AGP
AGP
– A ccelerated G raphics P ort • designed for Pentium II processor • used for graphics cards only • significantly speeds the performance in graphics app's (3D graphics, texture mapping and so on) • operates at the speed of the processor bus • AGP 1x (264 MBps), AGP 2x (528 MBps), AGP 4x (1056 MBps) 29
Block Diagram of the AGP Architecture
30 Source: www.pctechguide.com
AGP-based Graphics Card (example)
31 Source: www.howstuffworks.com
Parallel Port
• is most often used to connect a printer • some drives (e.g. ZIP) and other peripherals (e.g.
scanner) may piggyback on the parallel port • Canon connector, 25-pin female, marked (interface Centronics) LPT • standard IEEE 1284 provides bi-directional communication and faster data flow or PRN , • Compatible Mode (Centronics), Nibble Mode, Byte Mode, EPP (Enhanced Parallel Port) Mode, ECP (Extended Capabilities Port) Mode • EPP mode is mostly used 32
Serial Port
• is most often used to connect a mouse or a modem • Canon connector, 9- (or 25-) pin male, marked COM or RS 232 • slower than parallel port • today's computers usually use a mouse that connects to a PS/2 port (connector) 33
USB
•
USB
– U niversal S erial B us • up to 127 peripheral devices can be connected • supports fast data transfer rates • along with the signal USB carries a 5 V power supply so small devices, such as hand held scanners or speakers, do not have to have their own power cable • was designed to be user-friendly and it is truly PnP 34
Motherboard SL-77KV
Specification
www.soltek.com.tw
Processor:
AMD Athlon™
Chipset:
VIA APOLLO KX133, FSB 200 MHz, AGP 4x
Memory:
3 x 168-pin 3.3V DIMM Sockets, Supports 8MB to 768MB (maximum) DRAM Size, PC 133 compliant
Cache Memory:
Built-in to AMD Athlon™ Processor Module
On-Board EIDE:
2 x PCI Bus Master UATA 33/66 IDE ports (up to 4 ATAPI Devices) Supports for PIO Mode 3, 4, UATA 33/66 IDE & ATAPI CD-ROM 35
Motherboard SL-77KV
– cont'd
On-Board Super I/O:
4 x USB Ports 1 x Floppy Port, 2 x serial ports (high-speed 16550 FIFO UART Ports), 1 x Parallel Port with EEP/ECP/SPP Capabilities, PS/2 Mouse connector, Keyboard connector,
Expansion Slots:
1 x AGP Slot, 1 x AMR Slot, 5 x 32-bit PCI Bus Master Slots, 1 x 16-bit ISA Slots
Form Factor:
ATX Form Factor (190mm x 305mm)
BIOS:
AWARD Plug-and-Play BIOS Supports Advanced Power Management Function Flash Memory for easy upgrade
Other Features:
Supports AGP4x, PC 133 compliant, Ultra ATA/66, AC'97 Audio Function, H/W Monitor 36
Motherboard SL-77KV
– cont'd
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Motherboard SL-77KV
– cont'd
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Power Supply
• converts the AC input (230 V) to lower DC voltages (3.3 V, 5 V, 12 V, –5 V, –12 V) • the 3.3- and 5-volts are typically used by digital circuits, while the 12-volt is used to run motors in disk drives and fans • the main specification of a power supply is in watts (usually about 250 W or more) 39 Source: www.howstuffworks.com
Power Supply
– cont'd
According to PC Power & Cooling, Inc., some power consumption values (in watts) for common items in a personal computer are: AGP card PCI card floppy disk drive network interface card 50x CD-ROM drive RAM 5200 RPM IDE hard disk drive 7200 RPM IDE hard disk drive Motherboard (without CPU or RAM) 550 MHz Pentium III 733 MHz Pentium III 300 MHz Celeron 600 MHz Athlon 20 to 30 W 5 W 5 W 4 W 10 to 25 W 10 W per 128 MB 5 to 11W 5 to 15W 20 to 30W 30W 23.5W 18W 45W 40
Input/Output Processing
1. Programmed I/O
• The CPU executes a sequence of instructions, being in direct control of the I/O operations (sensing device status, read/write commands, etc.).
• When the CPU issues a command to the I/O module, it must wait until the I/O operation is complete.
• A lot of waisted time, because the CPU is much faster then devices.
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Input/Output Processing
2. Interrupt-driven I/O
• IRQ – Interrupt Request • After issuing an I/O command, the CPU has not to wait until the operation has finished; instead of waiting, the CPU continues with other useful work.
• When the I/O operation has been completed, the I/O module issues an interrupt signal on the bus.
• After receiving the interrupt, the CPU moves the data to/from memory, and issues a new command if more data has to be read/written.
Input/Output Processing
2. Interrupt-driven I/O
– cont'd Advantage over programmed I/O: • Instead of waiting the operation to be finished, the CPU can do some useful work.
Still a problem: • If large amounts of data have to be moved, this technique is still not efficient, because the CPU has to take care of each data unit separately, to move it to/from memory.
• Handling the interrupt also takes some time.
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Input/Output Processing
3. Direct Memory Access (DMA)
• An additional module on the system bus, the DMA module (controller), takes care of the I/O transfer for the whole sequence of data.
• The CPU issues a command to the DMA module and transfers to it all the needed information.
• The DMA module performs all the operations – it transfers all the data between I/O module and memory without going through the CPU .
• When the DMA module has finished, it issues an interrupt to the CPU.
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Device Manager – MS Windows 2000
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References
• http://www.pctechguide.com • http://www.howstuffworks.com
• http://www.zive.cz
• White, R.: How computers work. Que, Indianapolis 1999.
• Vrátil, Z.: Postavte si PC. BEN, Praha 1999.
• Horák, J.: Učebnice hardware. Computer Press, Praha 1998.
• Precht, M. – Meier, N. – Kleinlein, J.:
EDV-Grundwissen: Eine Einführung in Theorie und
Praxis der modernen EDV. Addison-Wesley, 1996. • Колесниченко, О. – Шишигин, И.: Аппаратные средства РС. «БХВ», Санкт-Петербург 1999.
• Вильховченко, С.: Современный компьютер: устройство, выбор, модернизация. «Питер», Санкт-Петербург 2000.
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