Data-driven control scheme for linear arrays: application to a stable insertion sorter

We present a strategy for designing stable insertion sorters based on linear arrays with data-driven control. The novelty of our approach lies in each data item carrying a control tag to specify how it is to be operated upon by a receiving cell and in performing two parallel comparisons within each cell. To assure first-in/first-out handling of equal key values, some data items must be marked to reflect their past histories. Such marking is conveniently carried out by modifying the data item's control tag. It is the combination of the above features that allows us to derive the first single-cycle priority queue that operates in fully pipelined mode, with no broadcasting of data values or control signals. By performing more than two parallel comparisons in each cell, the VLSI implementation cost of our stable sorter can be reduced. We show that highly cost-effective designs can be obtained by selecting an optimal cell size in terms of the number of comparators it contains.