An Efficient Mixed-mode Bist Technique

We propose a new built-in self-test (BIST) method based on a combination of a pseudo-random test method with a deterministic test. This enables us to reach a high fault coverage in a short test time and with a low area overhead. The main feature of the method is that there are no memory elements to store the deterministic test patterns; the test patterns are being produced by a transformation of the non-testing pseudo-random patterns. This transformation is being done by a purely combinational block, while we try to keep this block as small as possible. Our method can be apprehended as a generalization of a bit-fixing method. We synthesize the transformation logic by a slightly modified column-matching algorithm proposed before.