Subversion Repositories gppd

/*

 * This is a behavioral model for direct-form FIR digital filters.

 * The template parameters are:

 * T:           defines the prefered data type for the FIR filter

 * order:       defines the filter length

 * The constractor parameters are:

 * name:        any given name to the module

 * h:           filter coefficients array

 */

template<class T, int order>

SC_MODULE(fir)

{

        /// Design entity

        sc_in<bool> CLR;                        // Asynchronous active high reset

        sc_in<bool> CLK;                        // Rising edge clock

        sc_in<T>        firIN;                  // Comb stage input

        sc_out<T>       firOUT;                 // Comb stage output

        /// Internal signals

        sc_signal<T> delay[order];      // Internal signal used for delay

        /// Constructor

        SC_HAS_PROCESS(fir);

        fir(sc_module_name name, T* _h) :

        sc_module(name),

        h(_h)

        {

                SC_METHOD(algorithm);

                        sensitive << CLR << CLK.pos();

                        firOUT.initialize(0);

        }

        /// Concurrent processes

        /*

         * This process emulates the direct-form FIR filter algorithm.

         */

        void algorithm()

        {

                delay[0].write(firIN.read());

                T add = h[0] * firIN.read();

                for (unsigned int i = 1; i < order; i++)

                {

                        delay[i].write(delay[i-1].read());

                }

                for (unsigned int i = 1; i < order; i++)

                {

                        add = add + h[i] * delay[i-1];

                }

                firOUT.write(add);

        }

        /// Deconstructor

        ~fir()

        {

        }

        /// Constructor parent variables

        T* h;

};