Lec # 04 Computer Hardware (CPU & Memory)-1-1.pptx

presentation on computer hardware asnd memroy

1. 1 Intro to Computer Skills Lecture 04 Computer Hardware (Microprocessor and Memory)

2. TODAY’S LECTURE Today we learn about the microprocessor , the key component, the brain of a computer. We will learn about the function/building blocks of a microprocessor and its various sub-systems. We also familiarize with memory and its functions.

3. MICROPROCESSOR

4. MICROPROCESSOR A microprocessor is a computer processor on a microchip. Its sometime called logic chips or CPU . A microprocessor is designed to perform all calculations , decision making and control functions . Today’s state of the art processors including Pentium , Athalon , powerpc , etc, they are very complex circuits , it has tens of millions of transistors . They work at ultra fast speed , many can perform more than 1 billions operations per second. These all microprocessors are made up of same material , which is semi-conductor means they are made up of silicon .

5. A microprocessor is designed to perform: Arithmetic calculations Logic operations Use small number-holding areas called registers . Microprocessor operations include: Adding Subtracting Comparing two numbers Fetching numbers from one area to another .

6. When computer in turned on, the microprocessor is designed to get the first instruction from the basic input/output system (BIOS) that comes with the computer as a part of its memory. BIOS loads operating system into computer memory . A microprocessor is made from miniaturized transistors and other circuit elements on a single semiconductor integrated circuit (IC) . These are made up of semiconductor and silicon .

7. INTEGRATED CIRCUITS A microprocessor is an integrated circuit made up of silicon . A chip is also called IC (aka microchip or just chip). An IC is collection of several electronic components and these all components are miniaturized . One electronic component is millionth of a meter , means it is in microns . The thickness of human hair is 100 um (microns).

8. these components are… The components of IC Transistors Resistors Diodes Capacitors Wiring In any IC the most area covered is by its wiring (means that part of conductor who carry signal from one point to another).

9. TRANSISTORS In digital circuits, transistors are used as very fast electrical switches , and arrangements of transistors can function as logic gates .

10. MATERIALS The materials used in IC are: Silicon – semiconductor Copper – conductor (wires, the connecting path are made up of coppers) Silicon Dioxide - insulator

11. SILICON

12. MICROPROCESSOR SYSTEM Microprocessor System is different then microprocessor as the body is different then the brain. If we have the brain, but do not have hands, feet, then what is the benefit of this brain. Similarly, if we have microprocessor but do not have input , output and storage devices then this microprocessor is useless.

13. So in Microprocessor system , the major component is microprocessor , other components are input , output , storage and memory . Collectively it become Microprocessor system. Personal computer is one very popular example of Microprocessor System , another example of Microprocessor system is Micro-controllers .

14. MICRO-CONTROLLERS Micro-controller is a type of microprocessor system . The special thing is in micro-controller system these are all components i.e. microprocessor , memory of the program (ROM) , memory of the data (RAM) , I/O lines to communicate with peripherals & complementary recourses is on one chip . Means a complete computer on a chip . Micro-controllers are found in almost any electrical device e.g. washing machines , microwave ovens and in toaster etc…

15. MAIN MEMORY BOTTLENECK Microprocessor speed as compare to memory are quite faster. Today’s microprocessors can perform 1 operation in 1 nanosecond ( (10 -9 ) or 1 billionth of a  second ) , but the memory is respond in 100 nanosecond . It means if microprocessor say to memory it needs data, it can say it in 1 nanosecond, but he will get the response from memory in 100 nanoseconds or more. It means today’s slow memory making efficiency of a microprocessor less. It means microprocessor who are capable to perform at high speed due to slow memory are performing at low speed .

16. ON-CHIP(L1) CACHE MEMORY So, the 90 % of time microprocessor is working at full speed. So, this small , super fast memory that we locate on the same chip is called On-Chip(L1) Cache Memory . The frequently used data and instructions reside on the on-chip cache memory. So, whenever microprocessor needs data or instructions , its check in cache memory , if they don’t find those data & instructions then it checks the main memory . The size of cache memory is small 8KB to 64KB and its one of the building blocks that is located on a microprocessor .

17. Registers Registers Microprocessor Instruction Cache(L1) Arithmetic & Logic Unit Control Unit Bus Interface Unit Data Cache(L1) Instruction Decoder I/O RAM Memory Bus System Bus Floating Point Unit

18. CACHE MEMORY L2, cache memory , which is on a separate chip from the microprocessor. It is the small size and proximity to the microprocessor makes access times short , resulting in a boost in performance. It is an extremely fast, small memory between CPU and MAIN MEMORY whose access time is closer to the processing speed of the CPU . Cache is pronounced as “ cash ” .

19. BUS INTERFACE UNIT The Bus Interface unit is the hub of communication between microprocessor and outside world . The data & instruction coming from memory and I/O devices interact with Bus Interface Unit. Bus interface unit first of all identify these data & instruction that either these are data or instructions . If it is data then it send to data cache , if it is instruction then it send it to instruction cache. Similarly processed data in registers will be send to data cache from there it comes to bus interface unit, and send out from the processor. So, the bus interface unit do both works , it received data & instruction and send data out from the processor as well.

20. INSTRUCTION DECODER Instruction decoder analysis the instruction, which comes from instruction cache and decide these instructions will be send to ALU or FPU . It also simplify the instructions so that ALU or FPU understand it easily. Means it converts complex instructions into simple instructions .

21. ARITHMETIC & LOGIC UNIT(ALU) Also known as “ Integer Unit ” . In this building block mostly computations of microprocessor took place for example add , subtract , divide & multiply . Comparison is also took place here for example A is greater than B or A is less than B . Logical operations also took place. e.g. A AND B, A OR B.

22. Three types of operations took place here: Arithmetic Logic Comparison . Modern microprocessors have two and more ALU , the benefit of it two instructions can compute simultaneously.

23. FLOATING POINT UNIT (FPU) Another computation unit that found in modern microprocessor is FPU . Also known as Numeric Unit . ALU only deals with integers , the FPU deals with floating point numbers . Floating point numbers are those numbers which involved decimals or fractions . Through FPU you can store very very large and small numbers in compact form. So, FPU work is to multiply, divide, subtract or add fraction numbers .

24. REGISTERS The registers are attached with ALU & FPU , they are super fast memory like cache. When ALU & FPU are doing some calculations, then they store their intermediate calculations in registers on a temporary basis. Those calculation, which results you need after some time. When the calculation is finished, then this processed data from registers goes to data cache and then to bus interface unit from there either it goes out to memory or I/O devices.

25. Registers are part of the CPU (not main memory) of a computer. The length of a register, sometimes called its word size , equals the number of bits it can store.

26. COMMONLY USED REGISTERS

27. CONTROL UNIT Control unit is like a brain or heart of any microprocessor. Its most complex element of any microprocessor. Control unit is like, in war a field marshal or general is. If instructions come, the CU generate its order. If data have to come, the CU generate its order. It manages whole process of microprocessors.

28. MULTI-CORE PROCESSORS Dual-core refers to a CPU that includes two complete execution cores per processor . It has combine two processors and their caches and their controllers onto a single chip . They each have their own datapath and logic units . Example: If you are running a virus scan, and a word processor, you can set the virus scan to only run through one core, and word processor to work on the other core.

29. Multi-core Processor Dual-core Processor Quad-core Processor

30. ENHANCING THE CAPABILITY OF A MICROPROCESSOR The computing capability of a microprocessor can be enhanced in many different ways: By increasing the clock frequency . By increasing the word-size . Having more effective caching algorithm and right cache size . By increasing the RAM . By adding more functional units (e.g. ALU’s, FPU , etc) Improving the architecture (e.g. if a task is perform in 3, 4 cycles, it performs in 1 or 2 cycles)

31. MOORE’S LAW Gordon Moore who was the co-founder of Intel published a paper in 1965 . Stating in effect that at our rate of technological development and advancement in industry the complexity of integrated circuits double every year . Their prediction is still valid.

32. MEMORY

33. RANDOM ACCESS MEMORY (RAM) Primary storage of a computer is often referred to as RAM because of its random access capability . RAM’s are volatile memory . A computer’s motherboard is designed in a manner that the memory capacity can be enhanced by adding more memory chips . RAM is the place in computer, where OS , application programs and data in current use are kept. So that they can be quickly reached by processor.

34. TYPES OF RAM

35. SRAM SRAM is a type of memory that is faster and more reliable than the common DRAM (Dynamic RAM). The term static is derived from the fact that it doesn’t need to be refreshed like DRAM . Access time is around 10 nanoseconds . Both SRAM and DRAM are volatile , means that they lose their contents when the power is turned off.

36. DRAM Dynamic RAM needs to be refreshed thousands of times per second . The term dynamic indicates that the memory must be constantly refreshed . Access time is around 60-70 nanoseconds . DRAM is slower than SRAM.

37. CAPACITY OF RAM

38. ACCESS TIME OF RAM

39. READ ONLY MEMORY (ROM) ROM is a non-volatile memory chip. Data stored in ROM can only be read. ROM memory typically stores the instructions which is known as BIOS/system boot program . BIOS loads operating system into computer memory, check system hardware , like memory , I/O devices etc are functioning properly.

40. TYPES OF ROMs Type Usage. Manufactured-Programmed ROM Data is burnt by the manufacturer of the electronic equipment in which it is used. User-programmed ROM or Programmable ROM (PROM) User can load and store “read-only” programs and data in it. Erasable PROM (EPROM) User can erase information stored in it and the chip can be reprogrammed to store new information. Ultra Violet EPROM (UVEPROM) A type of EPROM chip in which information is erased by exposing the chip for some time to ultra-violet light. Electronically EPROM (EEPROM) A type of EPROM chip in which the stored information is erased by using high voltage electric pulses.