Chapter 7 - Fundamentals of computer organisation and architecture - Key Words Flashcards
Processor
A device that carries out computation on data by following instructions, in order to produce an output
Main Memory
Stores data and instructions that will be used by the processor
Fetch-execute cycle
The continuous process carried out by the processor when running programs
Random Access Memory (RAM)
Stores data and can be read to and written from
Chip
An electronic component contained within a thin slice of silicon
Read Only Memory (ROM)
Stores data and can be read from, but not written to (unless programmable ROM)
Bus
Microscopic parallel wires that transmit data between internal components
Data bus
transfers data between the processor and memory
Input/Output (I/O) controller
Controls the flow of information between the processor and the input an output devices
Word Length
The number of bits that can be addressed, transferred or manipulated as one unit
Address Bus
Used to specify a physical address in memory so that the data bus can access it
Addressable Memory
The concept that data and instructions are stored in memory using discrete addresses
Control Bus
Controls the flow of data between the processor and other parts of the computer
Von Neumann Architecture
A technique for building a processor where data and instructions are stored in the same memory and accessed via buses
Harvard Architecture
A technique for building a processor that uses separate buses and memory for data and instruction
Stored Program Concept
The idea that instructions and data are stored together in memory
Fetch - Execute Cycle
The continuous process carried out by the processor when running programs
Control Unit
Part of the processor that manages the execution of instructions
Arithmetic Logic Unit (ALU)
Part of the processor that processes and manipulates data
Clock
A device that generates a signal used to synchronise the components of a computer
Register
A small section of temporary storage that is part of the processor. Stores data or control instructions during the fetch - decode - excuse cycle
Status Register
Keeps track of the various functions of the computer such as if the result of the last calculation was positive or negative
Interrupt register
Stores details of incoming interrupts
Current Instruction Register (CIR)
Register that stores the instructions that the CPU is currently decoding/executing
Program Counter (PC)
Register that stores the address of the next instruction to be taken from main memory into the processor
Memory Buffer Register (MBR)
Register that holds data that is either written to or copied from the CPU (MDR)
Memory Data Register (MDR)
Register that holds data that is either written to or copied from the CPU (MBR)
Memory Address Register (MAR)
Register that stores the location of the address that data is either written to or copied form by the processor
Bus Width
The number of bits that can be sent down a bus in one go
Vectored Interrupt Mechanism
A method of handling interrupts by pointing to the first memory address of the instructions needed
Instruction Set
The patterns of 0s and 1s that a particular processor recognises as commands, along with their associated meanings
Opcode
An operation code or instructions used in assembly language
Operand
A value or memory address that forms part of an assembly language instruction
Addressing Mode
The way in which the operand is interpreted
Assembly Language
A way of programming using mnemonics
Mnemonics
Short codes that are used as instructions when programming e.g. LDR, ADD
Direct Address
The operand is the value
Immediate Address
The operand is the memory address or register
Data Transfer Operations
Operations that move data around between the registers and memory
Arithmetic Operations
Operations within an instruction set that perform basic maths, such as add and subtract
Shift Instructions
Operations within an instruction set that move bits within a register
Logical Operations
Operations within an instruction set that move the bits around within the operand
Branch Operations
Operations within an instruction set that allow you to move from one part of the program to another
