在altera的FPGA上实现直接数字频率合成，即用verilog实现DDS，输出正弦波形，在modelsim软件中仿真通过，已包含所有代码和工程以及二进制流文件。-The realization of direct digital frequency synthesis in the Altera FPGA, which is implemented by Verilog DDS, the output sine wave, through the simulation in Modelsim