`timescale 1ns/1ns module mux4_1( input [1:0]d1,d2,d3,d0, input [1:0]sel, output[1:0]mux_out ); //*************code***********// wire[1:0] d1,d2,d3,d0; wire[1:0]sel; reg [1:0]mux_out; always@(*) begin case(sel) 2'b11: mux_out=d0; 2'b10: mux_out=d1; 2'b01: mux_out=d2; 2'b00: mux_out=d3; endcase end //*************code***********// endmodule