Built-In Self-Test of configurable logic blocks in Virtex-5 FPGAs

A built-in self-test (BIST) approach is presented for the configurable logic blocks (CLBs) in Xilinx Virtex-5 field programmable gate arrays (FPGAs). A total of 17 configurations were developed to completely test the full functionality of the CLBs, including distributed RAM modes of operation. These configurations cumulatively detect 100% of stuck-at faults in every CLB. There is no area overhead or performance penalty and the approach is applicable to all levels of FPGA testing (wafer, package, and in-system). A novel output response analyzer (ORA) design, which is efficiently implemented in FPGAs, provides both an overall single-bit pass/fail result and optimal diagnostic resolution when faults are detected. The implementation of the BIST approach in all Virtex-5 FPGAs and experimental results are discussed.