Analysis and Design of Composable QDI FSMs

• Main Authors: Yao-Wei Tien, 田曜瑋
• Other Authors: Fu-Chiung Cheng
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/59290910044226477844

碩士 === 大同大學 === 資訊工程學系(所) === 101 === A large asynchronous sequential circuit is usually composed by many smaller asynchronous sequential circuits. The most common composition of asynchronous circuits is pipeline. To the best of our knowledge, no paper thoroughly discusses how to compose multiple asynchronous FSMs (Finite State Machines). A QDI (Quasi-Delay Insensitive) FSM composable model is proposed to construct a recomposible FSM by connect exiting QDI FSMs. We first carry out deadlock analysis of circuit composition and identify what types of circuit loops may cause deadlocks in the QDI FSMs. Solutions on how to break or prevent the deadlock are then proposed. Based on NCL_D and ROC QDI FSMs as basic components, we successfully compose a new recomposible Bit-counting circuit, a new recomposible GCD and a new recomposible CPU. The experimental results show that our new circuits have the same functionality with the corresponding synchronous circuits.