module p7seg(out,data);
     input [3:0]data ;   //來自BCD計數(shù)器的4位數(shù)據(jù)
     output [6:0] out;   //7段顯示器字段輸出
                                    // out[6:0]相當于a,b,c,d,e,f,g 
     reg [6:0] out; 
     always @(data )
        case (data)
            4'd0: out <= 7'b1111110 ;
            4'd1: out <= 7'b0110000 ;
            4'd2: out <= 7'b1101101 ;
            4'd3: out <= 7'b1111001 ;
            4'd4: out <= 7'b0110011 ;
            4'd5: out <= 7'b1011011 ;
            4'd6: out <= 7'b1011111 ;
            4'd7: out <= 7'b1110000 ;
            4'd8: out <= 7'b1111111 ;
            4'd9: out <= 7'b1111011 ;
            default:out <= 7'b0000000;
             //當data為4'hA~4'hF時，7段顯示器不亮
       endcase
endmodule