Minimizing the number of test configurations for different FPGA families

This paper describes an approach to minimize the number of test configurations for testing the logic cells of a RAM-based FPGA. The proposed approach is applied to the XILINX SPARTAN, 4000 and 3000 families. On these examples of FPGA, a bottom-up test technique is first used to generate test configurations for the elementary modules, then for a single logic cell, and finally for the m×m array of logic cells. In this bottom-up technique, it is shown that the key point is the minimization of the number of test configurations for a single logic cell. An approach is then described to define a minimum number of test configurations for a logic cell knowing the test configurations of its logic modules. This approach gives only 4 test configurations for the XILINX Spartan, 5 for the 4000 and 4 for the 3000 while the previous published works concerning Boolean testing of these FPGA families give 8 for the 4000 and 5 for the 3000