3 Lecture.pptx from the university of sindh

3 Lecture.pptx from the university of sindh

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  Instructor: Junaid JavedKorai Application of Information & Communication Technologies (AICT)
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  2 • Computer Memory •Primary Memory • Types of Primary Memory RAM (Random Access Memory) ROM (Read Only Memory) • Secondary memory • Cache Contents
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  4 Primary Memory:  Primaryis the computer memory that a processor access directly.  Data is temporary stored in primary memory.  The data stored in primary memory is lost when the computer power off. There are different types of Primary Memory 1. Ram 2. Rom 3. Register 4. Cache Memory
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  7 Memory Devices ❑ Ina computer, memory is one or more sets of chips that store data and/or program instructions, either temporarily or permanently.
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  8 MEMORY CHIP • Amemory chip is an integrated circuit made out of millions of capacitors and transistors that can store data or can be used to process code. • Memory chips can hold memory either temporarily through random access memory (RAM), or permanently through read only memory (ROM).
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  9 MEMORY CHIP • Readonly memory contains permanently stored data that a processor can read but cannot modify. • Memory chips comes in different sizes and shapes. • Some can be connected directly while some need special drives. • Memory chips are essential components in computer and electronic devices in which memory storage plays a key role
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  10 Memory Devices ❑ Ina computer, memory is one or more sets of chips that store data and/or program instructions, cither temporarily or permanently. ❑ Memory is a critical processing component in any computer Personal computers use several different types of memory, but the two most important arc called random access memory (RAM) and read-only memory (ROM). ❑ These two types of memory work in very different ways and perform distinct functions.
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  11 RAM • Random AccessMemory • RAM is like an electronic scratch pad inside the computer.
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  12 RAM
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  13 RAM  Random AccessMemory  RAM is like an electronic scratch pad inside the computer.  RAM holds data and program instructions while the CPU works with them.  When a program is launched, it is loaded into and run from memory.  it is loaded into memory for fast access.  As new data is entered into the computer, it is also stored in memory—but only temporarily.
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  14 RAM  Data isboth written to and read from this memory. (Because of this, RAM is also sometimes called read/write memory.)  Like many computer components, RAM is made up of a set of chips mounted on a small circuit board.  RAM is volatile, meaning that it loses its contents when the computer is shut off or if there is a power failure.  Therefore, RAM needs a constant supply of power to hold its data. For this reason, you should save your data files to a storage device frequently, to avoid losing them in a power failure.
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  15 RAM  RAM hasa tremendous impact on the speed and power of a computer.  The most common measurement unit for describing a computers memory is the byte .  The amount of memory it takes to store a single character such as a letter of the alphabet or a numeral.  When referring to a computer's memory, the numbers are often so large that it is helpful to use terms such as kilobyte (KB), megabyte (MB), gigabyte (GB), and terabyte (TB) to describe the values
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  16 RAM Units of measurefor computer memory and storage
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  17 Today’s personal computersgenerally have at least 256 million bytes (256 MB) of random access memory. Many newer systems feature 512 MB , 1GB ,2GB or more RAM RAM is of two types  Static RAM (SRAM)  Dynamic RAM (DRAM) Slots for memory SIMM Single inline memory module DIMM Dual inline memory module
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  18 SLOTS FOR MEMORY SIMM(Single In-line Memory Module) and DIMM (Dual In- line Memory Module) are older and modern RAM standards, respectively. SIMMs (obsolete) have a 32-bit path and pins on both sides connected together. DIMMs have a 64-bit path, separate pins on each side for faster data transfer, and are used in modern systems.
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  19 SIMM32 bit DIMM64 bit 8bits= 1byte 64bits=8byte Ram speed is 100MHz 8btye x 100= 800MB/s 8bits+8bits=2 8+8+ 8+8+8+8 8+8=8byte
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  20 SIMM32 bit DIMM64 bit 8bits= 1byte 64bits=8byte Ram speed is 100MHz 8btye x 100= 800Mps Calculate ram speed by Frequency x Bitrate=Mbps
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  21 Each generation ofDDR (Double Data Rate) RAM has brought significant improvements in speed, power efficiency, and capacity, while maintaining a fundamental operating principle of transferring data twice per clock cycle. Note that each generation is physically and electrically incompatible with the others. • DDR • DDR1 • DDR2 • DDR3 • DDR4 • DDR5
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  22 Generation Typical Speeds(MT/s) Operating Voltage Prefetch Buffer DIMM Pins (Desktop) Key Improvements DDR1 200–400 2.5V 2n 184 Doubled data rate of SDR SDRAM DDR2 400–800 1.8V 4n 240 Higher clock speed, lower power than DDR1 DDR3 800–1600 1.5V 8n 240 Lower voltage, doubled prefetch buffer, ASR/SRT features DDR4 2133–3200+ 1.2V 8n 288 Lower voltage, higher density, bank grouping, improved data integrity features (CRC, DBI, parity) DDR5 4800–6400+ (standard) 1.1V 16n burst + dual sub-channels 288 Dual 32-bit channels per module on-module PMIC, on-die ECC, vastly increased capacity and bandwidth
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  23 RAM AND PROCESSORTHERE IS PATH let suppose we called it SIMM, DIMM SIMM is single road DIMM is double road And DDR, DDR1 and so on. Are like size of vehicle , bigger the vehicle more data can be carried out The world's smallest transistor is 1nm long, physics be damned. Transistor size is an important part of improving computer technology. The smaller your transistors, the more you can fit on a chip, and the faster and more efficient your processor can be. There are 1000000000 nanometers in 1 meter. To convert from meters to nanometers, multiply your figure by 1000000000 .
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  25 PC100 is astandard for internal removable computer random access memory, defined by the JEDEC. PC100refers to Synchronous DRAM operating at a clock frequency of 100 MHz, on a 64-bit-wide bus, at a voltage of 3.3 V. PC100
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  26 RAM Static RAM (SRAM) Theword static indicates that the memory retains its contents as long as power is being supplied. However, data is lost when the power gets down due to volatile nature. SRAM chips use a matrix of 6-transistors and no capacitors. Transistors do not require power to prevent leakage, so SRAM need not have to be refreshed on a regular basis Minimum time to access data is require 10nano seconds, 6times more faster than DRAM Because of the extra space in the matrix, SRAM uses more chips than DRAM for the same amount of storage space, thus making the manufacturing costs higher. So SRAM is used as cache memory and has very fast access.
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  27 RAM Characteristic of theStatic RAM It has long life There is no need to refresh Faster Used as cache memory Large size Expensive High power consumption
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  28 RAM Dynamic RAM (DRAM) DRAM,unlike SRAM, must be continually refreshed in order to maintain the data. This is done by placing the memory on a refresh circuit that rewrites the data several hundred times per second. Need 1000 times to be refreshed in 1second Minimum time to access data is require 60nano seconds DRAM is used for most system memory because it is cheap and small. All DRAMs are made up of memory cells which are composed of one capacitor and one transistor.
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  29 SDRAM (synchronous DRAM)is a generic name for various kinds of dynamic random access memory (DRAM) that are synchronized with the clock speed that the microprocessor is optimized for. This tends to increase the number of instructions that the processor can perform in a given time. Dynamic RAM (DRAM)
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  30 Characteristics of theDynamic RAM  It has short data lifetime  Need to be refreshed continuously  Slower as compared to SRAM  Used as RAM  Lesser in size  Less expensive  Less power consumption RAM
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  31 Double data rate(DDR) is the advanced version of synchronous dynamic random access memory (SDRAM). SDRAM waits for clock signals before responding to control inputs. DDR uses both the falling and rising edges of the clock signal. SDR Single Data Rate. DDR Samsung s10 LPDDR5
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  32  Read-Only Memory Unlike RAM, Read-only memory (ROM) permanently stores its data, even when the computer is shut off.  ROM is called nonvolatile memory because it never loses its contents.  ROM holds instructions that the computer needs to operate.  Whenever the computer's power is turned on, it checks ROM for directions that help it start up, and for information about its hardware devices. ROM
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  33 ROM  TYPES OFROM • MROM (Masked ROM) • PROM • EPROM • EEPROM https://www.youtube.com/watch?v=OugI-niEy8c
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  34 ROM
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  35 ROM
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  36 ROM
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  37 Summary of Similarities: Bothresides within the processor chip. Both are faster than any other memory. Both are divided in various types/levels. Summary of Differences: Registers are both faster as well as nearest to cpu than cache. Registers are crucial for the cpu, without registers cpu will not perform in feasible amount of time. Cache can be seen as faster ram, which can help only if the same data is needed again (& again) or if we could predict which data will be needed next (or soon). Register & Cache
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  38 REGISTERS: They are smallmemories within the cpu. They are nearest to the cpu. There are many types of registers like Accumulator, Data Register, Program Counter, General purpose, etc. Thus they can be used for various tasks. Take example of accumulator register, its aim is to hold partial results and calculations. For example, if you want to multiply 789653 with 23442 i.e. (789653*23442), then you must store intermediate results and calculations before the final summation. This is the specific task of accumulator register. Take another example of Program Counter, it stores the address of the next instruction to be fetched. Thus there are various types of registers, some have specific tasks while others can be used for any purpose.
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  39 CACHE: It's a temporarystorage. It resides within the processor chip. It's both very fast as well as nearer to cpu than ram. The main aim is to try to fill it with the data which might be needed again soon. Hence it speeds up the computations if next time cpu finds the required data in cache itself (& thus no need to search & fetch data from slower ram). There are various techniques to efficiently use the limited cache memory like Least Recently Used (LRU), etc. These techniques tries to predict which data might be needed again & hence should be stored in cache. It's of generally three types/levels, L1, L2 & L3. L1 is the fastest but smallest. L3 is the largest but slowest.
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  40 Input and OutputDevices Useless if you could not interact Input devices accept data and instructions from the user or from another computer system (such as a computer on the Internet). Output devices return processed data to the user or to another computer system. The most common input device is the keyboard, which accepts letters, numbers, and commands from the user.
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  41 Input and OutputDevices by moving it across a flat surface and pressing its buttons. a personal computer with a keyboard, mouse, and microphone. A variety of other input devices work with personal computers, too: MOUSE
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  42 The trackball andtouchpad are variations of the mouse and enable you to draw or point on the screen. Input and Output Devices
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  43 The joystick isa swiveling lever mounted on a stationary base that is well suited for playing video games. Input and Output Devices
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  44 A scanner cancopy a printed page of text or a graphic into the computer’s memory. A microphone enables you to input your voice or music as data. A digital camera can record still images, which you can view and edit on the computer Input and Output Devices
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  45 The function ofan output device is to present processed data to the user. The most common output devices are the monitor and the printer The computer sends output to the monitor (the display screen) when the user needs only to see the output. It sends output to the printer when the user requests a paper copy—also called a hard copy—of a document
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  46 Some types ofhardware can act as both input and output devices.
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  47 Some types ofhardware can act as both input and output devices. A touch screen, for example, is a type of monitor that displays text or icons you can touch. When you touch the screen, special sensors detect the touch and the computer calculates the point on the screen where you placed your finger. Depending on the location of the touch, the computer determines what information to display or what action to take next.
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  48 Communications devices arethe most common types of devices that can perform both input and output. These devices connect one computer to another— Modem give facility to get input www.google.com and also show output But modem also such communication device which connect different computer A process known as networking. The most common kinds of communications devices are modems, which enable computers to communicate through telephone lines or cable television systems, and network interface cards (NICs), which let users connect a group of computers to share data and devices
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  49 Storage Devices You maythink of storage as an electronic file cabinet and RAM as an electronic worktable. Although the functions of storage and memory arc similar; they work in different ways. » There is more room in storage than in memory » Contents are retained in storage when the computer is turned off, » Storage devices operate much slower than memory chips
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  50 Types of SecondaryMemory
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  51 There are manytypes of computer storage, but the most common is the magnetic disk. A disk is a round, flat object that spins around its center. Magnetic Storage
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  52 Most personal computershave at least one non-removable hard disk (or hard drive In addition, there is also a diskette drive, which allows you to use removable diskettes (or floppy disks) Diskettes are used to load data onto the hard disk, to trade data with other users, and to make backup copies of the data on the hard disk. The device that holds a disk is called a disk drive. Magnetic Storage
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  53 HARD DISK
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  55 SSD
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  56 Like a memorystick, there are no moving parts to an SSD. Rather, information is stored in microchips. Conversely, a hard disk drive uses a mechanical arm with a read/write head to move around and read information from the right location on a storage platter. This difference is what makes SSD so much faster. SSD Solid State Drive
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  57 CD DRIVE
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  58 DVD DRIVE
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  59 PEN DRIVE
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  60 Blu-ray has finallywon the high definition format war, but that is just the beginning. Although Blu-ray discs look exactly the same as DVDs in size and shape there are many differences between the media, including storage capacity, laser technology, disc construction, image resolution and player compatibility. Blu Ray Disk
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  61 Blu Ray Disk