Von Neuman Architecture Flashcards
What is the CPU?
Central Processing Unit - the electronic circuit responsible for executing all the instructions received from the computer’s software and hardware.
Called the micro/processor
The CPU contains the CU, ALU and all the registers (various)
What are registers?
Registers are high-speed storage areas in the CPU. All data must be stored in a register before it can be processed.
What is the purpose of the ALU?
Arithmetic Logic Unit - allows arithmetic (add, subtract etc) and logic (AND, OR, NOT etc) operations to be carried out.
What is the MAR?
Memory Address Register - Holds the memory location of data that needs to be accessed
What is the MDR?
Memory Data Register - Holds data that is being transferred to or from memory
What is the AC
Accumulator - Where intermediate arithmetic and logic results are stored
What is the PC?
Program Counter - Contains the address of the next instruction to be executed
What is the CIR?
Current Instruction Register - Contains the current instruction during processing
What does the Control Unit do?
The control unit controls the operation of the computer’s ALU, memory and input/output devices, telling them how to respond to the program instructions it has just read and interpreted from the memory unit.
The control unit also provides the timing and control signals required by other computer components.
What are buses?
the means by which data is transmitted from one part of a computer to another, connecting all major internal components to the CPU and memory.
What does the address bus do?
Carries the addresses of data between the processor and memory - unidirectional
What does the data bus do?
Carries data between the processor, the memory unit and the input/output devices - bidirectional
What does the control bus do?
Carries control signals/commands from the CPU (and status signals from other devices) in order to control and coordinate all the activities within the computer
What is inside the memory unit?
The memory unit consists of RAM, sometimes referred to as primary or main memory. Unlike a hard drive (secondary memory), this memory is fast and also directly accessible by the CPU.
What is RAM like?
RAM is split into partitions. Each partition consists of an address and its contents (both in binary form).
The address will uniquely identify every location in the memory.
Why is RAM used by the CPU?
Loading data from permanent memory (hard drive), into the faster and directly accessible temporary memory (RAM), allows the CPU to operate much quicker.
