Built-in self-test with an alternating output

In this paper, a new compaction technique based on signature analysis is presented. Rather than comparing the final signature with the expected one after the test is completed, the binary output of the MISA is converted into an alternating binary signal by two simple cover circuits. An error is indicated whenever the alternation of the output signal is disturbed. This technique results in a higher fault coverage, improved fault diagnosis capability, a greater test autonomy in core-based designs, and early fault notification