module mux_256x1 (in,sel,out);
input [255:0] in;
input [7:0]sel;
output out;
wire out0_w, out1_w;

mux_128x1 m256_0(.in(in[127:0]),.sel(sel[6:0]),.out(out0_w));
mux_128x1 m256_1(.in(in[255:128]),.sel(sel[6:0]),.out(out1_w));
mux_2x1 m256_2(.a(out0_w),.b(out1_w),.sel(sel[7]),.out(out));

endmodule