Hardware Flashcards
Hardware
-physical components and the way they are connected
Software
-programs or lists of instructions to control the hardware to work properly
Peripherals
-the additional components
CPU
- Central processing unit
- is responsible for controlling most aspects of the computer system
- functionality of every computer system is centred on a processor
- function is to ~ process data, perform arithmetic and logical operations, store and retrieve information, communicate with peripheral devices
- every processor had its own language called machine language
- is the brain of the computer
CPU inside parts
CPU consists of three main parts
- control unit
- arithmetic/logic unit
- registers
Computer hardware
- CPU: central processing unit
- Memory: Dynamic RAM, static RAM
- Storage devices: hard drive
- Input devices: keyboard, mouse
- Output devices: screen, printer, network
- Communication devices: network, infrared, Bluetooth
Graphics board
- not all computer have them, sometimes the graphics capability built into motherboard
- can include its own processor and RAM
Computer Architectures
-von Neumaann (Princeton) Architecture (used in most computers)
Single memory source, requests instructions and data from a single location
-Harvard Architecture
Processor communicates two ways with an instruction memory source and a data source
-days and instructions kept desperate
Fetch - decode - execute
- Every general processor operates on the principle of fetch-decode-execute cycle
- A machine instruction is
- fetched from a program memory
- decoded and
- executed - The cycle is driven but a series of clock pulses
Timing (clock)
- All computers work on some sort of timing signal that is known as clock
- Clock is a periodic timing signal whose period is called a cycle
- The number cycles/second is called frequency whose units are Hertz
- Each processor operates at a certain frequency: the processor speed
Control unit
-Decides what to do next
-CU is responsible for fetching, decoding and executing instructions
-The CU issues logic signals that enables registers to output to, or receive info from, using an internal data pathway
Example
-memory operations
-arithmetic/ logical operations
-branch: choosing possible courses of action
Arithmetic/Logic Unit
- performs arithmetic and logical operations
- the CU fetches the appropriate data and issue a signals to the ALU to perform certain operation
- Arithmetic operations: add/Sub/Mult
- Logical operations: compare numbers to see which greater, check if Boolean is true
Registers
- are memory/like locations inside CPU
- for data and instructions being used right now
- hold operates being used in current arithmetic or logical operation or the result
- A typical CPU has only a few hundred to a a few thousand bytes of registers
System Bus Model
-communication between CPU, memory, and an input/output unit is handled by a shared pathway called the system bus
Storage
Two major categories of storage
- Primary (fast memories, small size)
- cache
- Main memory (RAM) - Secondary (slow memories, large size)
- hard disk
- removable
