what is inside a digital processor?

1)Input lowpass filter (anti-aliasing filter) – Analog input signal is filtered to be a band-limitedsignal by an input lowpass filter.

2)Analog to digital converter (ADC) – Signal is then sampled and quantized by an ADC

3)Digital computer or digital signal processor – Digital signal is processed by a digital circuit, often acomputer or a digital signal processor.

4)Digital to analog converter (DAC) -Processed digital signal is then converted back to ananalog signal by a DAC


5)Output lowpass filter (anti-imaging filter) – The resulting step waveform is converted to asmooth signal by a reconstruction filter called ananti-imaging filter.