For these studies scientist use IBM’s powerful supercomputer “Roadrunner” at National Laboratory Los Alamos. Earthquake studies-Supercomputers are used to study the Earthquakes phenomenon. Besides that supercomputers are used for natural resources exploration, like natural gas, petroleum, coal, etc. Weather Forecasting-Supercomputers are used for weather forecasting, and to study the nature and extent of Hurricanes, Rainfalls, windstorms, etc. Nuclear weapons testing-Supercomputers are used to run weapon simulation that can test the Range, accuracy & impact of Nuclear weapons. Popular Supercomputers IBM’s Sequoia, in United States Fujitsu’s K Computer in Japan IBM’s Mira in United States IBM’s SuperMUC in Germany NUDT Tianhe-1A in China 2. Mainframe computer:-Although Mainframes are not as powerful as supercomputers, but certainly they are quite expensive nonetheless, and many large firms & government organizations uses Mainframes to run their business operations. The Mainframe computers can be accommodated in large air-conditioned rooms because of its size. Super-computers are the fastest computers with large data storage capacity, Mainframes can also process & store large amount of data. Banks educational institutions & insurance companies use mainframe computers to store data about their customers, students & insurance policy holders. Popular Mainframe computers Fujitsu’s ICL VME Hitachi’s Z800 3. Minicomputers:-Minicomputers are used by small businesses & firms. Minicomputers are also called as “Midrange Computers”. These are small machines and can be accommodated on a disk with not as processing and data storage capabilities as super-computers & Mainframes. These computers are not designed for a single user. Individual departments of a large company or organizations use Mini-computers for specific purposes. For example, a production department can use Mini-computers for monitoring certain production process.
Popular Minicomputers K-202 Texas Instrument TI-990 SDS-92 IBM Midrange computers 4. Microcomputers. Desktop computers, laptops, personal digital assistant (PDA), tablets & smartphones are all types of microcomputers. The micro-computers are widely used & the fastest growing computers. These computers are the cheapest among the other three types of computers. The Micro-computers are specially designed for general usage like entertainment, education and work purposes. Well known manufacturers of Micro-computer are Dell, Apple, Samsung, Sony & Toshiba. Desktop computers, Gaming consoles, Sound & Navigation system of a car, Netbooks, Notebooks, PDA’s, Tablet PC’s, Smartphones, Calculators are all type of Microcomputers.
UNIT-I Microprocessor and Microprocessor Development Systems LECTURE -2 Microcomputer Organization: The basic components of a microcomputer are: 1) CPU 2) Program memory 3) Data memory 4) Output ports 5) Input ports 6) Clock generator. These components are shown in figure below: Microcomputer System Central Processing Unit: The CPU consists of ALU (Arithmetic and Logic Unit), Register unit and control unit. The CPU retrieves stored instructions and data word from memory; it also deposits processed data in memory. a) ALU (Arithmetic and Logic Unit) This section performs computing functions on data. These functions are arithmetic operations such as additions subtraction and logical operation such as AND, OR rotate etc. Result are stored either in registers or in memory or sent to output devices. b) Register Unit: It contains various register. The registers are used primarily to store data temporarily during the execution of a program. Some of the registers are accessible to the uses through instructions. c) Control Unit: It provides necessary timing & control signals necessary to all the operations in the microcomputer. It controls the flow of data between the μp and peripherals (input, output & memory). The control unit gets a clock which determines the speed of the μp
The CPU has three basic functions 1) It fetches an instructions word stored in memory. 2) It determines what the instruction is telling it to do.(decodes the instruction) 3) It executes the instruction. 4) It looks for control signal such as interrupts and provides appropriate responses. 5) It provides states, control, and timing signals that the memory and input/output section can use. Executing the instruction may include same of the following major tasks. 1. Transfer of data from reg. to reg. in the CPU itself. 2. Transfer of data between a CPU reg. & specified memory location. 3. Performing arithmetic and logical operations on data from a specific memory location or a designated CPU register. 4. Directing the CPU to change a sequence of fetching instruction, if processing the data created a specific condition. 5. Performing housekeeping function within the CPU itself in order to establish desired condition at certain registers. Program Memory: The basic task of a microcomputer system into ensure that its CPU executes the desired instruction sequence is the program properly. The instruction sequence is stared in the program memory on initialization- usually a power up and manual reset the processor starts by executing the instruction in a predetermined location in program memory. The first instruction of the program should therefore be in this location in typical μp basic system, the program to be executed is fixed one which does not change. Therefore μp program are store on ROM, or PROM, EPROM, EEPROM. In the trainer kit, ROM contains only the monitor program. The user program is not stored in ROM because it needs not to be stored permanently. Data Memory: A microcomputer manipulates data according to the algorithm given by the instruction in the program in the program memory. These instruction may require intermediate results to be stored, the functional block in μc have same internal reg. which can also be used if available for such storage external data memory is needed if the storage requirements is more. Apart from intermediate storage, the data memory may also be used to provide data needed by the program, to store some of the results of the program. Data memory is used for all storage purposes other than storage of program. Therefore, they must have head write capability RWM or RAM. It stores both the instructions to be executed (i.e. program) and the data involved. It usually contains ROM (Read memory). The ROM can only read and cannot be written into and is non volatile that is, it retains its contents when the power is turned off. A ROM is typically used to store instructions and data that do not change. For example, it stores the monitor program if a microcomputer. One can either read from or write into a RWM. The RWM is volatile, that is it does not retain its contents when the power is turned off. It is used to store user programmes & data which are temporary might change during the course of