The Research On Test Data Compression Of Digital System By Coding

The development of integrated circuit is one of the focuses of the contemporary technology. Its application has gone deep into every aspect of our life, and its high reliability has been appreciated. Sometimes, a tiny fault may cause the loss that we can never get over, especially in aviation, industrial control, finance and medical treatment. The test for the reliability of the integrated circuit has drawn more and more attention. Because of the rapid increase of the integration, the test has confronted with more and more challenges. At the moment, the research on the test of integrated circuit has the great values in both theory and application.The thesis makes research on test data compression of digital system. It reduces the transferring test data and the test application time effectively. Owing to easing up the contradiction between the great number of test data that caused by rapid increase of the integration, and the limited bandwidth of the test equipment, it has attracted more and more people in both academy and industry. The main work of the thesis are showed as following:At first, the dissertation introduces some related concepts in the test of digital system and the challenges to the SoC test. It analyses two methods of test data compression of SoC according to test resource partition, and categorizes the main encoding method at present in BOST novelly and attentively.In succession, the difference and marking compression method which is based on data block encoding is proposed. It introduces the difference operation into data block encoding, dynamically configures a lot of don't care bits in test set, combines with the idea of vector compatibility, and improves the compression ratio. Experiments show the method makes a very good tradeoff among many aspects, and gets a perfect result.In sequence, based on a serial of effective data flow encoding, the generalized alternative run-length coding is presented. The vectors in test set were divided into several groups by its run-length character. The drawbacks of many run-length encodings to some specific test set of circuits are overcome, and it becomes a robust encoding method.