ザイリンクスのplan aheadで以下のプログラムを実行したいのですがエラーが出できます。
エラーメッセージ　[HDLCompilers 26] "C:\Users\Daito\testPROJECT\testPROJECT.srcs\sources_1\imports\Desktop\seg7dec.v" line 7 Macro reference `b1110 is not defined

以下がプログラムです。
seg7dec.v(ファイル名）

module seg7dec(
input [3:0] SW,
output reg[7:0] nSEG,
output [3:0] nAN
);

assign nAN = 4`b1110;

always @* begin
case ( SW )
4h0: nSEG = 8b11000000;
4h1: nSEG = 8b11111001;
4h2: nSEG = 8b10100100;
4h3: nSEG = 8b10110000;
4h4: nSEG = 8b10011001;
4h5: nSEG = 8b10010010;
4h6: nSEG = 8b10000010;
4h7: nSEG = 8b11011000;
4h8: nSEG = 8b10000000;
4h9: nSEG = 8b10010000;
4ha: nSEG = 8b10001000;
4hb: nSEG = 8b10000011;
4hc: nSEG = 8b11000110;
4hd: nSEG = 8b10100001;
4he: nSEG = 8b10000110;
4hf: nSEG = 8b10001110;
default:nSEG = 8`bxxxxxxxx;
endcase
end
endmodule

seg7dec.ucf（制約ファイル名）

7segment display

NET "nSEG<0>" LOC = "L18";
NET "nSEG<1>" LOC = "F18";
NET "nSEG<2>" LOC = "D17";
NET "nSEG<3>" LOC = "D16";
NET "nSEG<4>" LOC = "G14";
NET "nSeG<5>" LOC = "J17";
NET "nSEG<6>" LOC = "H14";
NET "nSEG<7>" LOC = "C17";

NET "nAN<0>" LOC = "F17";
NET "nAN<1>" LOC = "H17";
NET "nAN<2>" LOC = "C18";
NET "nAN<3>" LOC = "F15";