|(architecture, parallel)||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
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
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.