模可变计数器是一种功能丰富、灵活性很强的时序逻辑电路。基于一种二维纳米尺度计算范例量子元胞自动机(QCA)设计了一种2位模可变计数器单元电路,该计数器由2个JK触发器和5个基本逻辑门构成。采用置零模式设置了计数器的初始状态,该方法为解决QCA时序逻辑电路设计中输出端随机初始状态的消除问题提供了一条有效途径。在QCA版图设计过程中,通过延迟匹配规则完成了反馈回路的时钟布线。QCADesigner软件仿真结果表明,设计的计数器具有正确的逻辑功能,当两位模式控制信号M2M1为01,10和11时,分别实现了模2、模3和模4计数。 Modular variable counter is a feature-rich, flexible timing logic circuit. A 2-bit modulo variable counter cell circuit was designed based on a two-dimensional quantum computing cellular automata (QCA) for nanoscale computing. The counter consisted of two JK flip-flops and five basic logic gates. Setting the initial state of the counter by using the zero-setting mode provides an effective way to solve the problem of eliminating the initial state of the output terminal in the QCA sequential logic circuit design. In the QCA layout design process, the clock routing of the feedback loop is done by delaying the matching rules. QCADesigner software simulation results show that the design of the counter has the correct logic function, when the two-mode control signal M2M1 01,10 and 11, respectively, to achieve the modulo 2, modulo 3 and modulo 4 count.