vhdl code for hamming window

You just need LUT and multiplier(s) to scale down your target (filter coefficients, fft output ...etc). It is normally pre-applied but if you want to apply it in vhdl code then you need to think of it as a set of scale factors. You need to decide how many taps you want and how to apply them (e.g. fully parallel).

To get 31 hamming set in Matlab:

w = hamming(31);

then scale up, round and insert in a LUT to be applied to target.