Efficient UBIST implementation for microprocessor sequencing parts
Résumé
An improved self-checking solution for the sequencing part of the MC 68000 microprocessor is presented. Compared with previous self-checking schemes for this microprocessor, the present scheme makes its possible to reduce the overhead and simplifies the implementation of both functional circuits, and checkers. The unified BIST (built-in self-test) method 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 integrated circuits, e.g., offline test (design verification, manufacturing, and maintenance test) and online concurrent error detection. An area overhead of about 27% is required, which is quite satisfactory in comparison with previous results.