An automated BIST approach for general sequential logic synthesis

An automated built-in self-test (BIST) technique for general sequential logic is described. This approach has been incorporated in a behavioral model synthesis system, providing automated implementation of BIST in very-large-scale-integration (VLSI) devices as well as programmable-logic-device (PLD)-based circuit packs. BIST can be directly used at all levels of testing from device testing through system diagnostics. It is based on selective replacement of existing system memory elements with BIST flip-flop cells that are connected to form a circular chain, performing data compaction and test pattern generation simultaneously. Two production VLSI devices have been implemented with this automated BIST approach. In each case, the total fault coverage was in excess of 96% and the logic overhead incurred was between 9.7 and 18.9%