Topic 7 - Computer organisation and architecture - Complete Flashcards
Define computer hardware?
The physical components of the computer system, which includes digital circuitry.
The processing hardware is necessary to gain a useable output from the system
Define Back store?
Normally a hard disk, which retains the data written on to it after the computer system has been switched off.
Could include other storage devices such as flash memory and removable disks.
Define input devices?
A form of inputting data into a computer. Typically a mouse, keyboard and microphone
Define output devices?
System output can be printed out by the user or displayed on a computer system
Define power supply?
Used to convert alternating current into low-voltage direct current to supply power to the internal components of the computer system
Define main memory?
Stores program instructions and data that are processed by the processor
Define address bus?
Specifies a physical address in main memory and the value that is to be read or written into the address is communicated via the data bus
Define control bus?
Manages data processing.
Sends signals to either write from the data bus to a memory address or a signal to read data from a memory address
Define input and output?
Controls signals received from the processor include input or output requests.
These control signals are then used to connect a system bus to specific I/O devices would input from keyboard and outputs from a monitor.
What are 4 operations processors do? S&S P L C I/O
Sorting & searching data
Performing calculations
Logical decision making
Control input/output and storage devices
Define Von Neumann architecture?
Data and instructions stored in a one memory location.
Data and instructions are transmitted through a shared data bus
Define Harvard architecture?
Data and instructions being stored in separate memories locations.
Instructions are fetched from instruction memory serially and data is fetched when needed by an instruction.
Define addressable memory?
Processor needs to address individual memory locations which have unique numeric codes.
What are the 3 steps taken to select a memory location?
Processor writes the numeric code into the address bus.
Processor sends a request to the control bus with instructions to read or write to the memory location.
The data that is being read or written will be transferred via the data bus.
Define the stored program concept?
Program is stored in main memory and machine code instructions are fetched and executed serially in the processor.
Define arithmetic logic unit (ALU)?
Performs arithmetic and logical operations Such as: - fixed point binary - Floating-point arithmetic - Logical operations (AND, OR, NOT) - Shift operations
Define Control unit?
Is to fetch program instructions from memory, to decode them and to execute them serially.
Define Clock?
System clock sends a signal to all computer components on a regular basis to synchronise all the programs.
Define Register?
A fast memory location that exists in the processor or the I/O controller.
General-purpose and dedicated registers.
Define general-purpose registers?
Can be used to hold instructions and data temporarily
R0, R1, R2…..R16
Define dedicated registers?
Are used by the processor to carry out a specific role.
State the 6 dedicated registers? ACC SR PC MAR MBR CIR
ACC - accumulator SR - status register PC - program counter MAR - memory address register MBR - memory buffer register CIR - current instruction register
Define the accumulator (ACC)?
Special register used as fast temporary storage by the ALU
Define the status register (SR)?
Used to hold status of various flags indicating its status:
positive, negative, carry bit, overflow
