`timescale 1ns / 1ps

module ImmediateExtender (
    input  [15:0] immediate,
    input  [ 1:0] extendop,
    output [31:0] extended_immediate
);

    assign extended_immediate = (extendop == 2'b00) ? {{16{immediate[15]}}, immediate}:
                                (extendop == 2'b01) ? {16'h0000, immediate}: {immediate, 16'h0000};
endmodule