基于butterworth的iir滤波器的verilog代码，已经通过测试。,err

verilog实现8阶的iir滤波器。对于刚学习verilog的朋友来说是一个易懂的学习资料。-verilog order to achieve the iir filter 8. For just learning verilog friend is a easy to understand learning materials.