Ip protection of mask data by rebuilding the design hierarchy using OASIS format

In this paper we present new development of intellectual properties(IP) protection software using OASIS format. By taking advantage of repetition presentation of OASIS, it becomes possible to express arrayed patterns without any generation of new cells, which also brings less overhead and further compaction of the result file. As a result, we could rebuild the hierarchy without cell generation and reduce the output file size. The experimental results show that there are no redundant cells generated and the file size has become 5 to 8 times smaller than conventional methods.