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Keiichi SUEMITSU Toshiaki ITO Toshiki KANAMOTO Masayuki TERAI Satoshi KOTANI Shigeo SAWADA
This paper proposes a new parallel method of producing the adjacent net pair list from the LSI layouts, which is run on workstations connected with the network. The pair list contains pairs of adjacent nets and the probability of a bridging fault between them, and is used in fault diagnosis of LSIs. The proposed method partitions into regions each mask layer of the LSI layout, produces a pair list corresponding to each region in parallel and merges them into the entire pair list. It yields the accurate results, because it considers the faults between two wires containing different adjacent regions. The experimental results show that the proposed method has greatly reduced the processing time from more than 60 hrs. to 3 hrs. in case of 42M-gate LSIs.
Masahiko OMURA Toshiki KANAMOTO Michiko TSUKAMOTO Mitsutoshi SHIROTA Takashi NAKAJIMA Masayuki TERAI
This paper proposes a new efficient method of characterizing a memory compiler in order to reduce the computation time and remove human error. The new features that make our method greatly efficient are the following three points: (1) high-speed circuit simulation of the whole memory module using a hierarchical LPE (Layout Parasitic Extractor) and a hierarchical circuit simulator, (2) automatic generation of circuit simulation input data from corresponding parameterized description termed the template file, and (3) carefully selected environmental conditions of circuit level simulator and minimizing the number of runs of it. We demonstrate the effectiveness of the proposed method by application to the single-port SRAM generators using 90 nm CMOS technology.
Hiroshi SHIROTA Satoshi SHIBATANI Masayuki TERAI
A fast rip-up and reroute algorithm for very large scale gate arrays is proposed. The automatic routing program for gate arrays usually consists of an initial routing process and rip-up and rerouting process. The rip-up and rerouting process eliminates the unconnects introduced by the initial routing process. There are two main reasons for leaving some unconnects: routing order dependency and local wire congestion. The existing rip-up and reroute algorithms can efficiently resolve unconnects caused by the routing order dependency. However, they cannot do unconnects caused by the local wire congestion. On the other hand, the proposed algorithm combines a `global' and `local' rip-up and reroute process and efficiently resolve unconnects caused by both of them. The `global' process reduces the local wire congestion by ripping up and rerouting global paths. The `local' process eliminates the unconnects, mainly caused by routing order dependency, by ripping up and rerouting local paths. The effectiveness of our method is demonstrated by our experimental results on industrial sea-of-gates (SOG) circuits and a well-known benchmark circuit.
Toshiki KANAMOTO Tetsuya WATANABE Mitsutoshi SHIROTA Masayuki TERAI Tatsuya KUNIKIYO Kiyoshi ISHIKAWA Yoshihide AJIOKA Yasutaka HORIBA
This paper proposes a new non-destructive methodology to estimate physical parameters for LSIs. In order to resolve the estimation accuracy degradation issue for low-k dielectric films, we employ a parallel-plate capacitance measurement and a wire resistance measurement in our non-destructive method. Due to (1) the response surface functions corresponding to the parallel-plate capacitance measurement and the wire resistance measurement and (2) the searching of the physical parameter values using our cost function and simulated annealing, the proposed method attains higher precision than that of the existing method. We demonstrate the effectiveness of our method by application to our 90 nm SoC process using low-k materials.