频率计，可以精确的测量仪器的工作周期，频率，测量精确度高-Frequency, precision measuring instruments for the duty cycle, frequency, high precision measurement

文章主要介绍了使用VHDL实现数字频率计的功能，其中包含了各部件的VHDL语言描述，仿真和大致硬件框图，对于初学EDA者大有帮助。-The article introduces the VHDL realization of the functionality of the digital frequency meter, which contains the hardware block diagram of the various components of the VHDL languag

Write VHDL specifications for an eight bit twisted ring counter based on each of the designs in the previous problem. Look at the synthesis report generated by the design tools (use the Spartan 2 xc2s15-cs144-6 part for this). How many fli