MAF

Moving Avergare Filter (MAF) in VHDL 2008 for DE0-NANO with FPGA Cyclone IV.

This filter works with fixed point that the number of bits depends on the ADC.

About the Moving Average Filter

A Moving Average Filter is a digital filter that average of the input's last M + 1 terms such as the following expresion:

        x[n] + x[n-1] + .... + x[n-M]

y[n] =  -----------------------------

                    M + 1

Using the second direct-form we can define h[n] like this: h[n] = x[n] + h[n-1]

So y[n] can be expresed in this waw: y[n] = (h[n] - h[n-M]) / (M + 1)

Structure of the filter

The Top Hierarchy is maftop.vhd that define all the filter's structure.

delayer.vhd

To generate from h[n-1] to h[n-M], flip-flops are used to delays.