The FIR consists of the following generic components :

fir_lib	:	Package for the FIR component
fir	:	N_taps-Wx x Wc Bits FIR (unrolled)
in_shifter_fir	:	in_shifter_fir : N_taps-Wx Bit shifter

The FIR component can be verified with this testbench :
   test_fir

This component implements an FIR (Finite Impulse Response) Filter.
An FIR filter of N_taps coefficients is defined by the following equation :

   

Each filter's sample, x_n-1, has a word length of Wx-bits, while
each filter's coefficient, C_i, has a word length of Wc-bits.
The f(x) FIR's output has a word length of Wx-bits.