Dynamic response of the double buffered frequency measurement method

A frequency measurement system using a double buffered method is designed for PC/AT compatible computers. The features and advantages of this double buffered method are experimentally verified. This method can be easily implemented using field-programmable gate arrays (FPGA) or application-specific integrated circuits (ASIC), which entail less hardware complexity compared with other methods. The hardware limit for maximum measured frequency can be increased to several hundred megahertz. The response time to an instantaneously increased frequency from 1.67 mHz to 7 MHz is less than two sampling periods. The menu-driven software graphically presents frequency versus time, for analyzing fast frequency change using rapid sampling, and measures the average frequency during long sampling periods