Implementations of Reconfigurable Logic Arrays on FPGAs

This paper presents a method to implement a reconfigurable logic array on an FPGA. To design circuits with 2-valued k-input LUTs, 2^k-valued logic is introduced. Standard benchmark functions as well as symmetric functions are efficiently implemented by a logic array with 2^k-valued variables. Number of products and number of bits to represent functions by the expressions with 2^k-valued variables for k = 1,2,3,4, and 5 are compared. Both sum-of-products expressions and EXOR sum-of-products expressions of 2^k-valued logic significantly reduces needed FPGA resources, when 2 les k les 5. Experimental results for benchmark functions and symmetric functions are shown. Implementations of arrays with 16-valued variables on Xilinx and Altera FPGAs are also shown.