实现电机M/T法测速的VHDL代码，只要修改cnt值大小即可修改M/T法切换的频率，当小于cnt时为T法，大于时为M法。-Motor M/T method velocimetry of the VHDL code, as long as the modified value of cnt to modify the size of M/T method of frequency switching, when cnt is less than for the T method, for M greater than law.