Systems Architecture

Systems Architecture

1. CPU

   • Cores
     • Multiple cores allow for more instructions to be processed at once
   • Processing Speed
     • Processing speed signifies how many instructions can be carried out by the CPU per second
     • Measured in Gigahertz (GHz)
   • Cache
     • Cache allows data to be stored closer to the CPU so it can be accessed faster
   • ALU (Arithmetic Logic Unit)
     • Used to perform the arithmetic and logic operations in the CPU
   • CU (Control Unit)
     • Clock
       • Pulses are sent out to the other components to coordinate their activities and ensure instructions are carried out and completed
       • The timing is controlled by a vibrating quartz crystal
     • Decoder
       • The CU interprets the instructions and decides what action to perform
   • ACC (Accumulator)
     • Stores the CPU's logic results
   • Registers
     • Registers are storage locations within the CPU itself
     • They can be accessed quickly

2. Embedded Systems

3. KEYWORDS

   • CPU
     • Central Processing Unit
   • RAM
     • Random Access Memory
   • Volatile
     • Emptied when power is turned off
   • ROM
     • Read Only Memory
   • Firmware
     • Permanent software programmed into the ROM
   • Non-volatile
     • Isn't lost when power is turned off
   • BIOS
     • Basic Input/Output System
   • Disc Thrashing
     • When a computer's virtual memory subsystem is in a constant state of paing
   • D.RAM
     • Dynamic RAM (usually known as RAM) is a type of volatile memory. It contains a transistor and a capacitor. To save data you need to store it elsewhere
   • S.RAM
     • Static RAM (usually known as cache) is a type of volatile memory. It contains 6 interlocked transistors and is faster than D.RAM. To save data you need to store it elsewhere
   • CU (Control Unit)
     • A component of the CPU that directs the operation of the processor
   • Busses
     • A set of parallel wires connecting two or more individual components of a computer system in order to pass signals between them
   • Peripherals
   • Processor
     • A part of the CPU that processes data & executes instructions
   • MAR (Memory Address Register)
     • Stores the data from which data will be fetched to the CPU
   • MDR (Memory Data Register)
     • Contains data to be stored in the computer storage
   • Main Memory
     • Where all the data in stored on the motherboard
   • Address Bus
     • Transfers data between devices. It is uni-directional
   • Data Bus
     • Transfer data between components in the CPU. It is bi-directional
   • Control Bus
     • Control signals are sent along the control bus, this instructs which data will be travelling to/from memory
   • Accumulator
     • Where the CPU's logic results are stored
   • PC (Program Counter
     • A Processor register that indicates where a computer is in its program sequence
   • ALU (Arithmetic Logic Unit)
     • Used to perform arithmetic and logic unit
   • I/O controller
     • Allows the interface between hardware devices external to the motherboard and the processor
   • I/O ports
     • Allows communication between an I/O device and the motherboard
   • Instruction
     • A list that tells the computer what to do
   • Execute
     • To carry out something
   • Embedded system
     • A computer system built within a larger device
   • Clock Speed
     • The speed that something can compute in cycles per second
   • Cache
     • A temporary storage space which allows quick access to data, the cache holds commonly used instructions
   • Core
     • Each CPU has a core in which instructions are processed
   • Multi-core processor
     • A processor that can work on more than one program or everything on one program
   • FDE (Fetch-Decode-Execute)
     • A standard process describes the steps needed for processing to take place
   • Instruction Register
     • The part of the CU that holds the instruction currently being executed or decoded
   • General Purpose Computers
     • A computer that should be able to perform most common computing tasks given appropriate application and required time
   • Dedicated Systems
     • A system capable of performing 1 specific task
   • Control Systems
     • Manages, commands, directs or regulates the behaviour of other devices or systems using control loops
   • Von Neumann
     • John von Neumann was a Hungarian-American mathematician, physicist and computer scientist. Developed the Stored program computer system containing both the computer program and the data it processes, removing the need for hardware modifications