This paper introduces the notion of referring forms as a new metric for analyzing sequential circuits from a functional perspective. Sequential circuits are modeled as causal stream functions, the outputs of which depend solely on the past and current inputs. Referring forms are defined based on the type expressions of functions and represent how a circuit refers to past inputs. The key contribution of this study is identifying a universal property in multiple clock domain circuits using referring forms. This theoretical framework is expected to enhance the comprehension and analysis of sequential circuits.

翻译：本文引入引用形式概念，作为从功能角度分析时序电路的新度量方法。时序电路被建模为因果流函数，其输出仅依赖于过去和当前的输入。引用形式基于函数类型表达式定义，表征电路如何引用历史输入。本研究的关键贡献在于利用引用形式识别多时钟域电路的通用性质。该理论框架有望提升对时序电路的理解与分析能力。