///////////////////////////////////////////////
// DPCM - Differential Pulse Code Modulation //
// Brazil-IP training / LAD / UFCG           //
// Transaction Level Netlist of DPCM project //
// Author: Jorgeluis Andrade Guerra          //
///////////////////////////////////////////////

struct sample {
	trans {
		short int s_value;  //sample value at transaction level
    }
	signals {
		signed[3] s_data;   //sample data at signals level
	}
}

struct unsat {			    //unsat - unsatured
	trans {
		short int u_value;  //unsatured value at transaction level
	}
	signals {
		signed[4] u_data;   //unsatured data at signals level
	}
}

module diff {
        input sample sample_in;
        output unsat diff_sat;
}

module sat {
	input unsat diff_sat;
	output sample sample_out;
}

module dpcm {
        input sample sample_in;
        output sample sample_out;

        channel unsat diff_sat;

        diff diff_i (.sample_in(sample_in), .diff_sat(diff_sat));
        sat sat_i (.diff_sat(diff_sat), .sample_out(sample_out));
}