With Time Parameters And Binary Determined Diagram (tbdd) And Its Application

With the high-speed development in microelectronic technology, the IC density has been increasing continually in recent years. On one hand, many conventional methods, such as truth table and canonical sum-of-products, are insufficient to represent Boolean Functions ; On the other hand, advances in VLSI technology still continue to increase its complexity. In order to guarantee the system working correctly and reliably, timing research has been advanced quickly in recent years. The influence of timing property over logical functionality in a circuit is becoming more and more important. So, finding a good approach to represent the logical and temporal information is a difficult issue before researchers now.Considering the above problems, this paper mainly includes three parts:First, as we well know, Ordered Binary Decision Diagrams (OBDD) as an efficient representation of Boolean Functions are widely used in CAD areas, such as logic verification , sequential machine equivalence, logic optimization, timing verification, and symbolic simulation etc. Although there already have been many papers presenting OBDDs in China, nowadays we haven't learnt reports on how to develop an OBDD software package efficiently and satisfactory experimental results. Carnegie-Mellon University successfully implemented a kind of OBDD package-----CMU BDD in early1990's. Our Fault-Tolerant Computing Center introduced this package in 1993. By carefully reading its important source programs and put it into concrete practice in SUN SPARK workstation, we have known the details about the mechanisms used in CMU BDD package. This dissertation will report what OBDDs are and key techniques implemented in CMU BDD package and then presents some typical extensions and improvements based on OBDDs.Second, after explaining Timed Boolean Functions (TBFs) as a representation formalism for logical and temporal analysis, this paper emphasis on a new efficientapproach for symbolic representation of TBFs-----Timed Binary Decision Diagrams(TBDD). TBDDs are a unified representation of temporal and logical behaviors of circuits, equivalent to TBFs both in timing and logical and hold the complete...