Efficient UBIST implementation for microprocessor sequencing parts

In this paper we first present an improved self-checking solution for the sequencing part of the Motorola MC 68000 microprocessor. compared to previous self-checking proposals for this microprocessor, the present scheme decreases the area overhead and simplifies the complexity of both functional circuits and checkers. In addition, the unified BIST method introduced recently, is applied to this scheme. This method uses a merging of self-checking and BIST techniques and allows a high fault coverage for all tests needed for the integrated circuits, e.g. off-line test for fabrication faults and for maintenance, and on-line concurrent error detection in the field.