Computer Architecture PDF

Computer Architecture Eng. Mohammad N. Olaimat Unit-01: Introduction to Computer Engineering 1. Computer Architecture & Organization Q1: What is computer architecture? Q2: What is computer organization? Computer architecture is concerne...

Computer Architecture Eng. Mohammad N. Olaimat Unit-01: Introduction to Computer Engineering 1. Computer Architecture & Organization Q1: What is computer architecture? Q2: What is computer organization? Computer architecture is concerned with the design of computer systems at the logical layer. It defines the logical structure of the system and its basic components and specifies how they relate with one another: It defines the computer’s instruction types, instruction formats, instruction operational codes (opcode), various data representation formats, I/O mechanisms, instruction & data memory requirements, a program’s logical flow effect on the components, and an algorithm for controlling an instruction processing cycle. In summary, Computer Architecture defines a computer system functionally. Computer Organization deals with the implementation of the computer architecture at the physical level. It is concerned with engineering the electronic circuits, peripheral structures, interfaces, connection layouts, and how instructions & data are stored and retrieved. In summary, Computer Organization defines a computer system at the physical layer. 2. Computer Structure and Function A computer is a complex system that is built of millions of elementary electronic components. To simplify the understanding of this complexity, the computer could be represented by a hierarchical system; that is a set of interrelated subsystems; each subsystem may, in turn, contain lower level subsystems, until we reach the lowest level of elementary subsystem (top-down view). At each subsystem, we are concerned with structure and function: Function The operation of each computer’s component comprising the structure. The basic functions are:  Data processing: Data transformation into other formats or converting data into information or producing actions.  Data storage: Performing short-term and long-term data storage functions and enabling its retrieval and manipulation.  Data movement: Performing I/O processing and data communication.  Control: The computer performing management tasks of its own resources and directing & regulating the performance of its integral functional components. Structure The hardware building-blocks of the computer system and their physical interconnections. Figure-1 provides a hierarchical view of the internal structure of a uniprocessor computer. There are four main structural components:  Microprocessor (MP): It includes the CPU which controls the operation of the computer's components and performs the data processing operations.  System-Memory: A device responsible for storing instructions and data. 1   I/O Modules: Microcontrollers & devices responsible for internal and external data & instruction transfer.  System Interconnection: Hardware pathways providing communication lines among the MP, system-memory, and the I/O modules. Figure-1: Uniprocessor Internal Computer Structure (simplified view) The CPU Structure consists of:  Control Unit (CU): Controls the operation of the CPU and hence the computer.  Arithmetic & logic unit (ALU): Performs the data processing functions.  Registers: Devices providing storage for the CPU.  CPU interconnection: Hardware pathways facilitating intercommunication among the CU, ALU, and the CPU registers. Multi-Processor Computers Terminology: System Board (Motherboard): It is the main printed circuit board in a computer that hosts the ICs. Other boards are called expansion boards. Integrated Circuit (IC): It is the opposite of an electronic discrete circuit; it is an electronic chip. Multiprocessor Computer: A computer that hosts multiple microprocessors, multi-core or discrete microprocessors. Multicore Computer: A computer that hosts multiple microprocessors which are integrated onto a single IC. Figure-2. Central Processing Unit (CPU): The device that fetches and executes instructions. It consists of an ALU, a CU, and registers. Core: A processing unit on a single processor chip. A core is typically more complex and specialized than a CPU is. Processor: It is an IC that hosts one core (unicore) or more cores (multicore). Core Structure 2 Instruction logic unit: This unit's task is fetching and decoding an instruction. Arithmetic & logic unit (ALU): It performs the operation specified by an instruction. Load/store logic unit: It manages the transfer of data to/from main memory via a cache device. Figure-2: View of multi-core computer 3 Figure-3 represents the layout of a systemboard hosting two Intel Xeon microprocessors. The main components are:  PCI-Express (PCIe) slots used for interconnecting computer peripherals.  Ethernet controller and Ethernet ports used for network connections.  USB sockets used for interconnecting peripheral devices.  Serial ATA (SATA) sockets for connection to disk memory.  Interfaces for DDR system memory chips.  Intel 3420 chipset which is an I/O controller used for managing direct memory access operations of peripheral devices. Figure-3: Systemboard of a multicore computer 3. Computer's Basic Components A computer's fundamental building blocks are the Electronic Gates and Memory Cells. An electronic gate is a device that implements a Boolean or logical function, such as an AND function of two or more operands, IF A AND B THEN C. The memory cell is a device that can store one bit of data; that is, the device can represent one of two states at any time. Figure-4 illustrates a logical view of Electronic Gates (Figure-4-A) and Memory Cells (Figure-4-B). Figure-4-A Figure-4-B 4 A computer engineer can correlate the computer’s functions with electronic gates and memory cells, as follows:  Data storage: Provided by memory cells.  Data processing: Provided by gates.  Data movement: The paths among components are used to transport data among the computer's devices as controlled by signals transmitted by electronic gates.  Control: The buses interconnecting computer's components transport control signals to/from Electronic Gates and Memory Cells. Electronic gates implement control signaling through their control ports. If a control port is ON, the gate is activated to perform its function on the data inputs and produces a data output; the output port is NULL otherwise. A memory cell would store the bit that is on its input port if the WRITE control port is ON and will place the bit that is stored in the cell on its output port if the READ control port is ON. Thus, a computer consists of gates, memory cells, and interconnections among these elements. More Fundamental Components Microprocessors, memories, and other digital devices are engineered from electronic logical gates and memory cells; in turn, logical gates and memory cells are fabricated from transistors and capacitors. The transistor is an electronic device that performs the function of an automated signal controller when a voltage signal is applied to it; thus, it could function as a logic gate (Figure-5). Hence, a collection of transistors may build a complex circuit of logic gates (AND, OR, NOR, XOR, NOT, NAND) to perform any function (mathematical / logical equation). A transistor may also function as a memory cell. Hence, computers may perform mathematical and logical calculations based on transistor circuits. A capacitor is also employed as a memory cell. A capacitor is an electronic component that stores electrons (bits!) in an electric field when voltage signal is applied to it (Figure-6). Figure-5 Figure-6 Older generations of computers used to be engineered from Electronic Discrete Circuits whereby electronic circuits are composed of discrete components- transistors, resistors, capacitors, and inductors- which are packaged in their own containers and soldered or wired onto the circuit boards. Discrete circuits are often used in home appliances; Figure-7(L). Modern computers are built of Electronic Integrated Circuits (IC) whereby an entire electronic circuit is fabricated of millions of transistors, resistors, capacitors, and inductors by being integrated collectively rather than assembling them. EICs are commonly known as microchips or chips. ICs are commonly used in high-performance electronic systems, such as computers, mobile phones, and medical devices. Figure-7(R). 5  Figure-7(L) Figure-7(R) 4. Evolution of the Intel MP Architecture 6 Historical highlights of the evolution of the Intel microprocessors: The Intel 4004 microprocessor was the first commercially produced microprocessor. It executes about 60,000 instructions ps. The 4004 was used in a variety of early electronic devices, including calculators and cash registers. It was also used in the first personal computer, the Altair 8800. 8086: The first MP to provide an instruction cache to prefetch instructions before they are executed. 8088 was used in IBM first PC. 80386: Intel first 32-bit machine. This was the first Intel processor to support multitasking. 80486: The 80486 MP introduced the use of instruction-pipelining. The 80486 also offered a built-in math coprocessor. Pentium: The Intel Pentium introduced the use of superscalar technology. Pentium II: The Pentium II incorporated the Intel MMX technology. Core: This is the first Intel MP with a dual core. Core 2: Core 2 extends the Core architecture to 64 bits. Core i9-13900K. It was manufactured in 2023 and has 24 cores. It was manufactured by using Intel's 7nm process and has NEW features, including: Support for DDR5 memory; Support for PCI Express 5; Integrated Intel Thread Director technology to improve system performance. 5. Embedded Systems Embedded systems are electronic systems that typically have software microprogrammed into hardware in contrast with general-purpose computers. Embedded systems are tightly coupled to their platforms and characterized by having real- time constraints, space limitations, and power constraints. Examples include cell phones, digital cameras, calculators, microwave ovens, home security systems, washing machines, lighting systems, thermostats, various automotive systems (e.g., transmission control, cruise control, fuel injection, anti-lock brakes, and suspension systems), and other types of automated systems. Internet of Things (IoT): The Internet of things (IoT) is a term that applies to a set of interconnected devices ranging from appliances to tiny sensors, to industrial machines. IoT systems are driven by embedded devices and are environment- aware. Microcontrollers: A microcontroller is a single device that contains a microprocessor, a ROM chip, RAM chip, a clock, and an I/O control unit. They are programmable but have constrained architecture, bus width within the range of 4-bit to 7 32-bit, operating frequency of the MHz range, supporting very limited human interaction. A microcontroller is never general-purpose; it is programmed for a predetermined task. ARM Microprocessors: The ARM MP is characterized by providing a high-performance, low-power-consumption, small- size, and low-cost processor for embedded systems. ARM powers smartphones and other handheld devices, including game systems, as well as other consumer products. ARM chips are the processors drive Apple’s iPod & iPhone, and Android phones. ARM’s products: Cortex family of microprocessors. 8