Abstract: Low power design has become an essential consideration for digital system design and low power bus design is one of the main branches. As the CMOS circuits characteristics, it can decrease the number of voltage transition between two consequential transmit states to reduce power dissipation effectively. Inverting bus technology is one of the major domains of low-power bus design. Bus-Invert and ShiftInv are two most important achievements in the domain. Previous work has focused on bus whose data obey even distribution, which one made some researches in. Otherwise, according to data correlation with each other, bus data actually obey normal distribution in the real world. The research results show that ShiftInv coding works better than Bus-Invert coding for both buses.

Key words: normal distribution, design for low-power bus, Bus-Invert coding, ShiftInv coding

摘要： 低功耗设计已成为数字系统设计中必须考虑的问题，而总线低功耗设计是其中的重要分支。由于CMOS电路功耗的特性，降低总线上相邻两个传输数据状态的电压变化能有效降低总线功耗，降低总线翻转技术已成为降低总线功耗的重要研究领域之一，而Bus-Invert编码、ShiftInv编码是这一研究领域中的重要研究成果。以往的研究主要集中在遵从随机均匀分布的数据总线上，对该状态下的总线编码进行研究。由于总线上数据的相关性，现实中的总线数据往往服从正态分布的规律。通过对两种总线翻转编码技术的研究，得出对于服从均匀分布和正态分布的数据总线，ShiftInv编码技术降低功耗的能力均优于Bus-Invert编码技术。

关键词: 正态分布, 总线低功耗设计, Bus-Invert编码, ShiftInv编码