//
// Title        : (109) Dual JK-FFs with Preset and Clear
// File name    : 109.v
// Date         : 2000/12/08  Ver1.0
// Company      : Future Technology Ltd.
//

//----------------------------------------------------------
//  Module
//----------------------------------------------------------

module U109 (
        XCLR,
        XPR,
        CLK,
        J,
        K,
        Q
      );

    input       XCLR;
    input       XPR;
    input       CLK;
    input       J;
    input       K;
    output      Q;

//----------------------------------------------------------
//  Using register
//----------------------------------------------------------
    reg         Q;

    always@(posedge CLK or negedge XCLR or negedge XPR)begin
        if(XCLR==1'b0)begin
            Q    <= 1'b0;
        end else if(XPR==1'b0)begin
            Q    <= 1'b1;
        end else if(J==1'b1 && K==1'b0)begin
            Q    <= 1'b1;
        end else if(J==1'b0 && K==1'b1)begin
            Q    <= 1'b0;
        end else if(J==1'b1 && K==1'b1)begin
            Q    <= ~Q;
        end
    end

endmodule