BIST linear generator based on complemented outputs

Autonomous linear finite state machines with both complemented and uncomplemented register outputs (mixed-output ALFSMs) have been investigated for their use as deterministic and pseudo-random test vector generators in a BIST scheme. The authors describe a method for deriving the feedback connections of the mixed-output ALFSM given a deterministic sequence of n n-bit wide test vectors. They also show that the state graph structure is preserved thus enabling the generation of maximum-length sequences if the characteristic polynomial of the connectivity matrix is primitive. An example is given to illustrate the synthesis method of a mixed-output ALFSM based test vector generator. A better solution is obtained compared to conventional uncomplemented output ALFSM.<>