von neumann architecture

1 definition found

von neumann architecture - Free On-line Dictionary of Computing (26 May 2007) :

  von Neumann architecture
  von Neumann machine
  
     <architecture, computability> A computer architecture
     conceived by mathematician John von Neumann, which forms the
     core of nearly every computer system in use today (regardless
     of size).  In contrast to a Turing machine, a von Neumann
     machine has a random-access memory (RAM) which means that
     each successive operation can read or write any memory
     location, independent of the location accessed by the previous
     operation.
  
     A von Neumann machine also has a central processing unit
     (CPU) with one or more registers that hold data that are
     being operated on.  The CPU has a set of built-in operations
     (its instruction set) that is far richer than with the
     Turing machine, e.g. adding two binary integers, or
     branching to another part of a program if the binary integer
     in some register is equal to zero (conditional branch).
  
     The CPU can interpret the contents of memory either as
     instructions or as data according to the fetch-execute cycle
     .
  
     Von Neumann considered parallel computers but recognized the
     problems of construction and hence settled for a sequential
     system.  For this reason, parallel computers are sometimes
     referred to as non-von Neumann architectures.
  
     A von Neumann machine can compute the same class of functions
     as a universal Turing machine.
  
     [Reference?  Was von Neumann's design, unlike Turing's,
     originally intended for physical implementation?]
  
     (http://salem.mass.edu/~tevans/VonNeuma.htm).
  
     (2003-05-16)