chapter 1

• Computer Organization


  Encompasses all physical aspects of computer systems, e.g. circuit design, control signals, memory types. How does a computer work?
• Computer Architecture


  Logical aspects of system implementation as seen by the programmer, e.g. instruction sets, instruction formats, data types, addressing modes. How do I design a computer?
• There is no clear distinction between matters related to computer organization and matters relevant to computer architecture
• Principle of Equivalence of Hardware and Software


  Anything that can be done with software can also be done with hardware, and anything that can be done with hardware can also be done with software (assuming speed and cost are not a concern)
• Rock's Law


  The cost of capital equipment to build semiconductors will double every four years
• Hierarchical system


  • Set of interrelated subsystems, each may contain lower-level subsystems, essential to both design and description
• Basic functions a computer can perform

  • Data processing
  • Data storage
  • Data movement
  • Control
• 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 provides communication among CPU, main memory, and I/O
• Major structural components of the CPU

  • Control Unit
  • Arithmetic and Logic Unit (ALU)
  • Registers
  • CPU Interconnection
• Core


  An individual processing unit on a processor chip, may be equivalent in functionality to a CPU on a single-CPU system
• Processor


  A physical piece of silicon containing one or more cores, the computer component that interprets and executes instructions
• Cache Memory is smaller and faster than main memory, used to speed up memory access
• 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
• Motherboard is a multilayer printed circuit board (PCB) that holds and interconnects chips and other electronic components
• Chip is a single piece of semiconducting material, typically an integrated circuit (IC)
• Expansion boards and expansion slots (sockets) are also part of the computer structure
• The IAS computer (Van Neumann) was a prototype of all subsequent general-purpose computers, using the stored program concept
• The fundamental building block of digital circuits is the transistor, which can change its electrical state when pulsed
• Discrete transistors were manufactured separately, packaged in their own containers, and soldered or wired together onto circuit boards
• Integrated circuits combined multiple transistors on a single chip, leading to the Third Generation of computers from 1965-1971
• Early computers


  • DEC PDP-1
  • Univac 1100
  • IBM 360
  • DEC PDP-8
  • DEC PDP-11
  • Cray-1 supercomputer
• Transistors


  • Fundamental building block of digital circuits used to construct processors, memories, and other digital logic devices
  • Active part is made of silicon or other semiconductor material that can change its electrical state when pulsed
  • In normal state the material may be nonconductive or conductive
  • The transistor changes its state when voltage is applied to the gate
  • Discrete component - a single, self-contained transistor that were manufactured separately, packaged in their own containers, and soldered or wired together onto Masonite-like circuit boards
• Integrated circuits


  • Data storage provided by memory cells
  • Data processing provided by gates
  • Data movement - the paths among components are used to move data from memory to memory and from memory through gates to memory
  • Control - the paths among components can carry control signals
• Chip production


  1. Ingot of purified silicon - 1 meter long, sliced into thin wafers

  2. Chips are etched - much like photography, using UV light through multiple masks to lay down circuits

  3. Process takes about 3 months
• Very large scale integrated circuits (VLSI)

  • Have more than 10,000 components per chip
  • Enabled the creation of microprocessors
  • The first was the 4-bit Intel 4004, later versions such as the 8080, 8086, and 8088 spawned the idea of "personal computing"
• The fifth Generation: ULSI Computers (1982 - ????)
• Moore's Law


  Observed number of transistors that could be put on a single chip was doubling every year, pace slowed to a doubling every 18 months in the 1970's but has sustained that rate ever since
• Consequences of Moore's law

  • The cost of computer logic and memory circuitry has fallen at a dramatic rate
  • The electrical path length is shortened, increasing operating speed
  • Computer becomes smaller and is more convenient to use in a variety of environments
  • Reduction in power and cooling requirements
  • Fewer interchip connections
• 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
  • Often tightly coupled to their environment, giving rise to real-time constraints imposed by the need to interact with the environment
• Generations of deployment culminating in the IoT

  • Information technology (IT)
  • Operational technology (OT)
  • Personal technology
  • Sensor/actuator technology
• Embedded operating systems


  Two general approaches - take an existing OS and adapt it for the embedded application, or design and implement an OS intended solely for embedded use
• Application processors


  Defined by the processor's ability to execute complex operating systems, general-purpose in nature
• Dedicated processors


  Dedicated to one or a small number of specific tasks required by the host device, can be engineered to reduce size and cost
• Typical Microcontroller Chip Elements
• Deeply embedded systems


  • Subset of embedded systems with a processor whose behavior is difficult to observe, uses a microcontroller rather than a microprocessor, is not programmable once the program logic has been burned into ROM, has no interaction with a user, are dedicated single-purpose devices, often have wireless capability and appear in networked configurations, have extreme resource constraints
• ARM (Advance RISC Machine)


  Refers to a processor architecture that has evolved from RISC design principles and is used in embedded systems, family of RISC-based microprocessors and microcontrollers designed by ARM Holdings, known for their small die size and low power requirements, probably the most widely used embedded processor architecture in the world
• ARM Products


  • Cortex-A
  • Cortex-R
  • Cortex-M (Cortex-M0, Cortex-M0+, Cortex-M3, Cortex-M4, Cortex-M7, Cortex-M23, Cortex-M33)