module alu_decoder (
input [1:0] opcode,
output reg [3:0] alu_op
);
always @* begin
case (opcode)
// Write solution her
2'b00:alu_op=4'b0001;
2'b01:alu_op=4'b0010;
2'b10:alu_op=4'b0100;
2'b11:alu_op=4'b1000;
default:alu_op=4'b0000;
endcase
end
endmodule