基于FPGA的数字频率计的设计11利用VHDL 硬件描述语言设计,并在EDA(电子设计自动化) 工具的帮助下,用大规模可编程逻辑器件(FPGA/ CPLD) 实现数字频率计的设计原理及相关程序-FPGA-based design of digital frequency meter 11, the use of VHDL hardware descr iption language design, and EDA (electronic design automation) tools with the help of large-scale programmable logic devices used (FPGA/CPLD) digital frequency meter and the design principle related procedures