Chapter 1: Basic Concepts and Computer Evolution
Computer Architecture
•Attributes of a system visible to the programmer •Have a direct impact on the logical execution of a program
History of Computers Third Generation: Integrated Circuits
1958 - the invention of the integrated circuit Discrete component Single, self-contained transistor Manufactured separately, packaged in their own containers, and soldered or wired together onto masonite-like circuit boards Manufacturing process was expensive and cumbersome The two most important members of the third generation were the IBM System/360 and the DEC PDP-8
Multicore Computer Structure
Central processing unit (CPU) Portion of the computer that fetches and executes instructions Consists of an ALU, a control unit, and registers Referred to as a processor in a system with a single processing unit Core An individual processing unit on a processor chip May be equivalent in functionality to a CPU on a single-CPU system Specialized processing units are also referred to as cores Processor A physical piece of silicon containing one or more cores Is the computer component that interprets and executes instructions Referred to as a multicore processor if it contains multiple cores
CPU Major structural components:
Control Unit Controls the operation of the CPU and hence the computer Arithmetic and Logic Unit (ALU) Performs the computer's data processing function Registers Provide storage internal to the CPU CPU Interconnection Some mechanism that provides for communication among the control unit, ALU, and registers
Structure and Function
Hierarchical system : Set of interrelated subsystems Hierarchical nature of complex systems is essential to both their design and their description Designer need only deal with a particular level of the system at a time : Concerned with structure and function at each level Structure : The way in which components relate to each other Function : The operation of individual components as part of the structure
Cache Memory
Multiple layers of memory between the processor and main memory Is smaller and faster than main memory Used to speed up memory access by placing in the cache data from main memory that is likely to be used in the near future A greater performance improvement may be obtained by using multiple levels of cache, with level 1 (L1) closest to the core and additional levels (L2, L3, etc.) progressively farther from the core
History of Computers Second Generation: Transistors
Smaller Cheaper Dissipates less heat than a vacuum tube Is a solid state device made from silicon Was invented at Bell Labs in 1947 It was not until the late 1950's that fully transistorized computers were commercially available
The Internet of Things (IoT)
Term that refers to the expanding interconnection of smart devices, ranging from appliances to tiny sensors Is primarily driven by deeply embedded devices Generations of deployment culminating in the IoT: Information technology (IT) PCs, servers, routers, firewalls, and so on, bought as IT devices by enterprise IT people and primarily using wired connectivity Operational technology (OT) Machines/appliances with embedded IT built by non-IT companies, such as medical machinery, SCADA, process control, and kiosks, bought as appliances by enterprise OT people and primarily using wired connectivity Personal technology Smartphones, tablets, and eBook readers bought as IT devices by consumers exclusively using wireless connectivity and often multiple forms of wireless connectivity Sensor/actuator technology Single-purpose devices bought by consumers, IT, and OT people exclusively using wireless connectivity, generally of a single form, as part of larger systems It is the fourth generation that is usually thought of as the IoTand it is marked by the use of billions of embedded devices
Microprocessors
The density of elements on processor chips continued to rise More and more elements were placed on each chip so that fewer and fewer chips were needed to construct a single computer processor 1971 Intel developed 4004 First chip to contain all of the components of a CPU on a single chip Birth of microprocessor 1972 Intel developed 8008 First 8-bit microprocessor 1974Intel developed 8080 First general purpose microprocessor Faster, has a richer instruction set, has a large addressing capability
Embedded Systems
The use of electronics and software within a product Billions of computer systems are produced each year that are embedded within larger devices Today many devices that use electric power have an embedded computing system Often embedded systems are tightly coupled to their environment This can give rise to real-time constraints imposed by the need to interact with the environment Constraints such as required speeds of motion, required precision of measurement, and required time durations, dictate the timing of software operations If multiple activities must be managed simultaneously this imposes more complex real-time constraints
Function
There are four basic functions that a computer can perform: Data processing Data may take a wide variety of forms and the range of processing requirements is broad Data storage Short-term Long-term Data movement Input-output (I/O) - when data are received from or delivered to a device (peripheral) that is directly connected to the computer Data communications - when data are moved over longer distances, to or from a remote device Control A control unit manages the computer's resources and orchestrates the performance of its functional parts in response to instructions
History of Computers First Generation: Vacuum Tubes
Vacuum tubes were used for digital logic elements and memory IAS computer: Fundamental design approach was the stored program concept Attributed to the mathematician John von Neumann First publication of the idea was in 1945 for the EDVAC Design began at the Princeton Institute for Advanced Studies Completed in 1952 Prototype of all subsequent general-purpose computers
IBM System 370 Architecture
- IBM System/370 architecture Was introduced in 1970 Included a number of models Could upgrade to a more expensive, faster model without having to abandon original software New models are introduced with improved technology, but retain the same architecture so that the customer's software investment is protected Architecture has survived to this day as the architecture of IBM's mainframe product line
There are four main structural components of the computer:
CPU - controls the operation of the computer and performs its data processing functions Main Memory - stores data I/O - moves data between the computer and its external environment System Interconnection - some mechanism that provides for communication among CPU, main memory, and I/O
Registers
Memory buffer register (MBR) • Contains a word to be stored in memory or sent to the I/O unit • Or is used to receive a word from memory or from the I/O unit Memory address register (MAR) Memory address register (MAR) • Specifies the address in memory of the word to be written from or read into the MBR Instruction register (IR) • Contains the 8-bit opcode instruction being executed Instruction buffer register (IBR) Instruction buffer register (IBR) • Employed to temporarily hold the right-hand instruction from a word in memory Program counter (PC) • Contains the address of the next instruction pair to be fetched from memory Accumulator (AC) and multiplier quotient (MQ) • Employed to temporarily hold operands and results of ALU operations
Family Characteristics
Similar or identical instruction set Similar or identical operating system Similar or identical operating system Increasing speed Increasing speed Increasing number of I/O ports Increasing number of I/O ports Increasing memory size Increasing memory size Increasing cost Increasing cost
Organizational attributes include:
•Hardware details transparent to the programmer, control signals, interfaces between the computer and peripherals, memory technology used
Architectural attributes include:
•Instruction set, number of bits used to represent various data types, I/O mechanisms, techniques for addressing memory
Computer Organization
•The operational units and their interconnections that realize the architectural specifications
