A new hierarchical built-in self-test with on-chip diagnosis for VLIW processors

This paper presents a new in-the-field self-test approach for a specific VLIW processor model with emphasis on the diagnostic capability of the test. It is intended to be used as start-up test in-the-field in order to localize permanently defect components in a VLIW processor model, which provides self-repair capability. In order to overcome the drawbacks of several existing self-test techniques, a combination of them in a hierarchical manner is provided. By this, the data path of the VLIW processor can be checked within a very short time and at a fine grained diagnostic level. The results show that the required diagnostic resolution for the used processor model with self-repair capability can be obtained with a relatively small hardware overhead of about 6%.