Clarified FFT output width.

libraries/dsp/fft/src/vhdl/fft_pkg.vhd

@@ -70,8 +70,12 @@ package fft_pkg is
   -- Check consistancy of the FFT parameters
   function fft_r2_parameter_asserts(g_fft : t_fft) return boolean;  -- the return value is void, because always true or abort due to failure
 
-  -- FFT input and output widths
+  -- FFT input width
   function func_fft_in_scale_w(g_fft : t_fft) return natural;
+
+  -- FFT output width
+  --                 Removed MSbits     Quantized data    Rounded LSbits
+  --   c_raw_dat_w = c_fft.out_gain_w + c_fft.out_dat_w + c_raw_fraction_w
   function func_fft_raw_dat_w(g_fft : t_fft) return natural;
   function func_fft_raw_fraction_w(g_fft : t_fft) return natural;