INTRODUCTION TO INFORMATION & COMMUNICATION TECHNOLOGY (ICT) LECTURE 2 : WEEK 2 CSC-111-T Credit : (2 + 1) / Week 2 TEXT AND REF. BOOKS Text Book: Peter Norton (2011), Introduction to Computers, 7 /e, McGraw-Hill Reference Book: Gary B (2012), Discovering Computers, 1/e, South Western Deborah (2013), Understanding Computers, 14/e, Cengage Learning June P & Dan O (2014), New Perspective on Computer, 16/e 1
3 MOBILE ALERT Kindly Switch Off your Mobile/Cell Phone OR Switch it to Silent Mode Please 4 GOOGLE SITE ADDRESS FOR LECTURE NOTES AND STUDY MATERIAL DOWNLOAD, PLEASE VISIT : https://sites.google.com/site/shucsc110/ OR TYPE SHUCSC110 & GOOGLE 2
COMPONENTS OF SYSTEM 5 Presented by: Flt. Lt. Shujaat H. Butt (R) MS. Telecomm. & Network Management, UK Masters (CS), Bahria University Khi, Pakistan Prince2 Project Management (Foundation) Certified Microsoft Certified Professional (MCP) 6 Learning Objectives To get understanding of the followings, Components of Computer System Motherboard, CPU (ALU, CU, Registers etc) Computer Memory and its types Primary, Secondary, RAM, ROM, Cache, BUS etc Parts of computer system Memory Speed The Information Processing Cycle Computer Data & Users 3
Parts of the Computer System 7 Computer systems have four parts Hardware Software Data User Computer Hardware 8 Computer hardware refers to the physical parts or components Monitor, mouse, keyboard, data storage, hard drive disk (HDD), system unit (graphic cards, sound cards, memory, motherboard and chips) Mechanical devices in the computer Anything that can be touched 4
9 Computer Hardware 10 Motherboard (Main or Logic Board) The motherboard is the piece of computer hardware that can be thought of as the "back bone" of the PC The motherboard serves to connect all of the parts of a computer together i.e. The CPU, memory, hard drives, optical drives, video card, sound card and other ports and expansion cards all connect to the motherboard directly or via cables 5
Typical Motherboard 11 12 What is a CPU? Central processing unit (CPU) is the hardware within a computer that carries out instructions of a computer program by performing the basic arithmetical, logical, and input/output operations of the system More than one CPU is called multiprocessing Modern CPUs are microprocessors, contained on a single chip Some integrated circuits (ICs) can contain multiple CPUs on a single chip; called multi-core processors 6
CPU : 3 Major Components 13 Arithmetic Logic Unit (ALU) Control Unit (CU) Registers CPU : 3 Major Components 14 ALU (arithmetic logic unit) An ALU is a digital circuit used to perform arithmetic and logic operations Performs calculations and comparisons Arithmetic (Addition, Subtraction, Multi, Division etc) Logical operations (NOT, AND, OR etc) Modern CPUs contain very powerful and complex ALUs 7
CPU : 3 Major Components 15 CU (control unit): performs fetch/execute cycle Functions: Moves data to and from CPU registers and other hardware components Accesses program instructions and issues commands to the ALU Subparts: Memory management unit: supervises fetching instructions and data Characteristics of CU 16 In charge of all the operations being carried out Direct the system to execute instructions Communicate between the memory and the ALU Load data and instructions from the secondary memory (HDD) to the main memory (RAM) as required 8
Registers 17 A register is a small amount of storage available as part of a CPU, Data registers can hold numeric values such as integer Address registers hold addresses General purpose registers (GPRs) can store both data and addresses Example: Program counter (PC) or instruction pointer determines next instruction for execution Registers 18 Use of Registers Scratchpad for currently executing program Holds data needed quickly or frequently Stores information about status of CPU and currently executing program Address of next program instruction Signals from external devices 9
19 Characteristics of Registers Small, permanent storage locations within the CPU Manipulated directly by the Control Unit Wired for specific function Size in bits or bytes (not MB like memory) Can hold data, an address or an instruction The more registers a CPU has available, the faster it can work System Block Diagram 20 10
Processor Fabrication 21 Performance and reliability of processors has increased with improvements in materials and fabrication techniques Transistors and integrated circuits (ICs) Microchips and microprocessors First microprocessor (1971) 2,300 transistor Current memory chip 300 million transistors Processor Fabrication 22 11
What is Memory? 23 Physical devices used to store programs (sequences of instructions) or data on a temporary or permanent basis for use in a computer Two types of Memory Secondary Memory Primary or Main Memory Secondary Memory 24 Non-volatile and persistent in nature and is not directly accessed by a processor Secondary memory is accessed only by the primary or main memory Slower than P.M but larger in size and cheap Data can be stored for later retrieval HDD, Tape Drives etc 12
25 Primary Memory Computer memory that a processor or computer accesses first or directly Allows a processor to access running execution applications and services Random Access Memory (RAM) Read Only Memory (ROM) 26 RAM: Random Access Memory DRAM (Dynamic RAM) Most common, cheap Volatile: must be refreshed (recharged with power) 1000 s of times each second SRAM (Static RAM) Faster than DRAM and more expensive than DRAM Volatile Frequently small amount used in cache memory for high-speed access used 13
27 RAM: Random Access Memory 28 RAM: Random Access Memory 14
29 ROM - Read Only Memory Non-volatile memory to hold software that is not expected to change over the life of the system EEPROM Electrically Erasable Programmable ROM Slower and less flexible than Flash ROM Flash ROM Faster than disks but more expensive Uses BIOS: initial boot instructions and diagnostics 30 Bus The physical connection that makes it possible to transfer data from one location in the computer system to another A Computer bus used to transfer data, signals or power between some of the components of computer Group of electrical conductors for carrying signals from one location to another Line: each conductor in the bus 15
31 Bus 3 kinds of signals 1.Data (alphanumeric, numerical, instructions) 2.Addresses 3.Control signals Connect CPU and Memory 32 Speed and Power What makes a computer fast? Microprocessor speed Bus line size Availability of cache Flash memory Parallel processing 16
33 Computer Processing Speed Time to execute an instruction Millisecond (10-3 ) Microsecond (10-6 ) Nanosecond (10-9 ) Modern computers Pico second (10-12 ) We are almost there 34 Cache Memory Small block of very fast temporary memory Speeds up data transfer Stores/keeps instructions and data used most frequently or most recently 17
35 Types of Cache Memory Internal cache Level 1 (L1) Attached to microprocessor Up to 128KB External cache Level 2 (L2) Separate chips 256KB or 512 KB SRAM technology Cheaper and slower than L1 Faster and more expensive than normal ram memory 36 Computer Memory Computer memory is binary (0 or 1) (on or off) The byte is the standard unit of measurement A byte is composed of 8 bits (binary digits) Typical units of measurement: 1 KB (kilobyte) = 1024 bytes 1 MB (megabyte) =1024 kilobytes or 1 million bytes 1 GB (gigabyte) =1024 megabytes or 1 billion bytes 18
37 Memory Speed Cache Level 0 (L0) Micro operations cache 6 KB in size Level 1 (L1) Instruction cache 128 KB in size Level 1 (L1) Data cache 128 KB in size. Best access speed is around 700 GB/second Level 2 (L2) Instruction and data 1 MB in size. Best access speed is around 200 GB/sec Level 3 (L3) Shared cache 6 MB in size. Best access speed is around 100 GB/second Level 4 (L4) Shared cache 128 MB in size. Best access speed is around 40 GB/second 38 Memory Speed Main memory Gigabytes Best access speed is around 10 GB/second Disk storage Terabytes Best access speed is from a solid state drive is about 600 MB/second 19
39 Types of Processing Serial processing Execute one instruction at a time Fetch, decode, execute, store Parallel Processing Multiple processors used at the same time Can perform trillions of floating-point instructions per second (teraflops) Ex: network servers, supercomputers 40 Types of Processing Pipelining Instruction s action need not be complete before the next begins Fetch instruction 1, begin to decode and fetch instruction 2 20
41 Learning Outcome Students have adequate conceptual understanding of, Components of Computer System Motherboard, CPU (ALU, CU, Registers etc) Computer Memory and its types Primary, Secondary, RAM, ROM, Cache, BUS etc Parts of computer system Memory Speed The Information Processing Cycle Computer Data & Users 42 END OF LECTURE Any Questions!!! 21