Structure and Function of the processor Flashcards
What does the arithmetic and logic unit do?
The ALU completes all arithmetic and logical operations.
What does the control unit do?
A part of the processor which directs operations in the CPU.
What are registers?
Small memory cells that operate at high speeds.
Where do all the arithmetic, logic or shift operations occur?
They occur in registers.
What does the program counter (PC) do?
Holds the address of the next instruction.
In which part of the CPU do all calculations take place?
ALU
Where are the intermediate ALU results stored?
Accumulator
What does the memory address register do?
Hold the address of a location that is to be read from or written to.
What does the memory data register do?
Temporarily stores data that has just been read from or the data needs to be written.
What does the current instruction register (CIR) do?
Hold the current instruction divided up into operand and opcode.
What is a bus?
A set of parallel wires connecting two or more components together.
What is the system bus?
The collect of the address, data and control bus.
What is the data bus?
A bi-directional bus used to transport data and instructions between components.
What is the control bus?
A bi-directional bus that transmits control signals between internal and external components.
What is the address bus used for?
Used to transmit the memory address specifying where data is to be sent from or retrieved from.
What does adding a wire to the address bus do to the addressable locations?
Doubles the number of addressable locations.
What does bus request indicate?
Indicates a device is requesting to access the data bus.
What does bus grant indicate?
Indicates the CPU has granted access to the data bus.
What does memory write do?
Causes the data on the data bus to be written into the addressed location.
What does memory read do?
Causes the data from the addressed location to be placed onto the data bus.
What does the interrupt request control signal indicate?
Indicates that a device is requesting access to the CPU.
What is the clock control signal used for?
It is used to synchronise instructions.
What is assembly language?
A programming language where mnemonics are used to represent instructions.
What is opcode?
Used to determine the type of instruction and what hardware to use to execute it.
