The study of the measured frequency in EPM3128 based on the VHDL language

The chip design based on EDA technology is becoming the mainstream of the electronic system design. The objective of this project is to achieve a better method of the measurement and the multiplication of the measured frequency using the EPM3128. Both the VHDL programms and the timing emulations are achieved detailedly. In order to realized the measurement and the multiplication of the mearsured frequency, the synchronization should be achieved. The number of the crystal oscillator signal is been recorded, and then the CPU reads the data in the counter through the fip-latch. What´s more, because of the n-bit right shift, the data recorded in the measurement is reduced to the 1/2ⁿ times. A narrow pulse will be outputted each time a expiration of the counter arrives.