FPGA实现频率测量的3种方法（直接测量法，间接测量法，等精度测量法）工程源码

+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ ; Legal Partition Candidates ; +-----------+-------+----------------+--------------+----------------+--------+-----------------+---------------+-----------------+-------+----------------+--------------+------------------+-------------------+ ; Hierarchy ; Input ; Constant Input ; Unused Input ; Floating Input ; Output ; Constant Output ; Unused Output ; Floating Output ; Bidir ; Constant Bidir ; Unused Bidir ; Input only Bidir ; Output only Bidir ; +-----------+-------+----------------+--------------+----------------+--------+-----------------+---------------+-----------------+-------+----------------+--------------+------------------+-------------------+