Pass the specification values to the object rather than accepting the default values for N, Fc1, and Fc2. Include the sampling frequency Fs as the final input argument. Design the filter and plot the results.

使用DPCM语音压缩的简单实验，主控芯片使用C8051F020，8位的ADC1进行采集，采样频率8KHz，12位的DAC0进行输出-Voice compression using DPCM simple experiment, the master chip using C8051F020, 8-bit ADC1 collection, sampling frequency 8KHz, 12-bit output of a DAC0