本文讨论一种数字频率采样接口。对于差动的双频率输入信号,应该完成采集、求差及累积运算,并按严格的时序向计算机进行数据传送。这些功能通过一个同步控制逻辑完成。对内同步控制方法及同步时钟周期确定的原则作了说明。作为一种可编程接口电路,多种功能的数据采集模式通过相应的接口软件来实现。 This article discusses a digital frequency sampling interface. For the differential dual-frequency input signal, it should complete the acquisition, subtraction and accumulation operations, and according to strict timing data transmission to the computer. These functions are accomplished through a synchronous control logic. The principle of internal synchronization control method and synchronization clock cycle is described. As a programmable interface circuit, a variety of functions of the data acquisition mode through the appropriate interface software to achieve.