基于锁相环Top-down的建模方法在MATLAB环境下建立数字锁相环完整的仿真模型，并用SIMULINK对数字锁相环的仿真模型进行仿真。　-Top-down phase-locked loop based on the modeling method in MATLAB environment DPLL set up a complete simulation model, and use of digital phase-locked loop SIMULINK simulation mod

经典锁相环，MATLAB simulink编写，点开即可运行，对于学习锁相环的同学很有帮助(Classic phase-locked loop, written in MATLAB Simulink, point to run, for students learning phase-locked loop helpful)