John Von Neumann

Von Neumann Architecture: A von Neumann architecture machine, designed by physicist and mathematician John von Neumann (1903–1957) is a theoretical design for a stored program computer that serves as the basis for almost all modern computers.


MAR(Memory Address Register): In a computer, the Memory Address Register (MAR) is the CPU register that either stores the memory address from which data will be fetched from the CPU, or the address to which data will be sent and stored. In other words, MAR holds the memory location of data that needs to be accessed.




MDR(Memory Data Register): A memory buffer register (MBR) or memory data register (MDR) is the register in a computer's processor, or central processing unit, CPU, that stores the data being transferred to and from the immediate access storage. ... When data is fetched from memory and placed into the MDR, it is written to go in one direction.




Program Counter: A program counter is a register in a computer processor that contains the address (location) of the instruction being executed at the current time. As each instruction gets fetched, the program counter increases its stored value by 1.


Accumulator: In a computer's central processing unit (CPU), an accumulator is a register in which intermediate arithmetic and logic results are stored. ... Modern computer systems often have multiple general purpose registers that operate as accumulators, and the term is no longer as common as it once was.




ALU(Arithmetic Logic Unit): An arithmetic logic unit is a combinational digital electronic circuit that performs arithmetic and bitwise operations on integer binary numbers. This is in contrast to a floating-point unit, which operates on floating point numbers.






CU(Control Unit): The control unit (CU) is a component of a computer's central processing unit (CPU) that directs the operation of the processor. It tells the computer's memory, arithmetic/logic unit and input and output devices how to respond to the instructions that have been sent to the processor.




Cache: Definition of: cache (1) To store data locally in order to speed up subsequent retrievals. Pronounced "cash." See Web cache and browser cache. (2) Reserved areas of memory (RAM) in every computer that are used to speed up processing.




Fetch/Execute: The fetch execute cycle is the basic operation (instruction) cycle of a computer. During the fetch execute cycle, the computer retrieves a program instruction from its memory. It then establishes and carries out the actions that are required for that instruction.




Busses: The bus in a PC is the common hardware interface between the CPU and peripheral devices. Parallel buses use multiple lines (wires) for data. Serial buses use one line for data.