Page 169 - Hardware Implementation of Finite-Field Arithmetic
P. 169

152    Cha pte r  S i x


                             b 0  a 0                  coef c(x)  d(x)


                             0    1                1    0    1    0   final
                                                 mult_in        c_or_d(x)
                              mod p
                        a 0  inverter                   mod p
                                inv_ab                multipliers
                                                                  z(x)
                                               c(x)
                          mod p                           coefc_or_d (x)
                         multiplier
                                                   mod p
                    coef        b(x)             subtractors
                                              d(x)   cd(x)
                             mod p
                     a(x)  multipliers
                                               0    1   sel_bd
                               coefb (x)
                                               w (x)  w
                        mod p                         0        f  –1 f (x)
                                                               0
                       subtractors
                           ab(x)
                  b(x)/x                                    mod p
                                                           multipliers
                          ab(x)/x
                                                               w f  –1 f (x)
                                                                0 0
                   0    1   sel_bd
                                                        mod p
                                                      subtractors
                       next_b (x)
                                              w(x) – w f  –1 f (x)
                                                    0 0
                initially:  ce  ce_bd      (w (x) – w f  –1 f (x))/x
                                                 0 0
                     h(x)
                                                   initially:  ce  ce_bd
               b (x)                                   g(x)
                                                 d(x)
                initially:  ce  ce_ac
                     f(x)
                                                   initially:  ce  ce_ac
                                                       zero
                     a(x)
                                                       c(x)
               FIGURE 6.2  Binary algorithm.



                  z: out polynomial;
                  done: out std_logic
               );
               end binary_algorithm_polynomials;
                  The VHDL architecture corresponding to the circuit of Fig. 6.2
               follows:
   164   165   166   167   168   169   170   171   172   173   174