Source : Free On-Line Dictionary of Computing

systolic array
     
         (By analogy with the regular pumping
        of blood by the heart) An arrangement of processors in an
        array (often rectangular) where data flows synchronously
        across the array between neighbours, usually with different
        data flowing in different directions.  H. T. Kung and Charles
        Leiserson publish the first paper describing systolic arrays
        in 1978 [reference?].
     
        Each processor at each step takes in data from one or more
        neighbours (e.g. North and West), processes it and, in the
        next step, outputs results in the opposite direction (South
        and East).
     
        An example of a systolic {algorithm} might be matrix
        multiplication.  One matrix is fed in a row at a time from the
        top of the array and is passed down the array, the other
        matrix is fed in a column at a time from the left hand side of
        the array and passes from left to right.  Dummy values are
        then passed in until each processor has seen one whole row and
        one whole column.  At this point, the result of the
        multiplication is stored in the array and can now be output a
        row or a column at a time, flowing down or accross the array.
     
        See also {Ruby}, {SISAL}.
     
        (1998-07-01)