Verilog help (module Instantiations and inverting a pin)

[pathare]

Im trying to write a program for a decoder using two smaller decoders instantized in a module. I can bring in the decoders no problem but I need to invert the enable bit on one of the two decoders and I cant figure out how.

module mydecoder24vlog(en, in, out);
    input en;
    input [1:0] in;
    output [3:0] out;
	 reg out;
	 
	 always@(in or en)
	 begin
		if(en == 1)
		begin
			case(in)
				0: out = 4'b0001;
				1: out = 4'b0010;
				2: out = 4'b0100;
				3: out = 4'b1000;
			endcase
		end
			
		if(en == 0)
		begin
			out = 0;
		end
	end
endmodule

this is the 2 to 4 decoder, im trying to put two together to make a 3 to 8 decoder below.

/*module mydecoder24vlog (en, in, out);
	 input en;
	 input [1:0] in;
	 output [3:0] out;
endmodule*/
	 
module mydecoder38vlog(in, out);
    input [2:0] in;
    output [7:0] out;
	 wire wire1;
	 
	 
	 
	 mydecoder24vlog decoder1 (in[2], in[1:0], out[7:4]);
	 mydecoder24vlog decoder0 (in[2], in[1:0], out[3:0]);
	 // assign wire1= decoder0 en;
	  
	  //not inverter0(wire1, in[2]);

endmodule

this includes a few things ive tried and commented out. The best way ive gotten it work was just by inverting the in[2] in one by saying in[!2]. this would synthesize and run but not quite right. the help for my assignment recommends using the "not inverter0(wire1, in[2]) piece but I dont think that will work unless I can link the inverter to the enable bit by assigning wire to the enable bit of the 2-4 decoder. I cant seem to make that work though that was why I did the full module header and commented it out. I would appreciate any help.
Thank you

 

[degibson]

I'm assuming this is homework?

You're on the right track with continuous assignment to wire1.

1. Look up the terms: Verilog bitwise not. (as opposed to logical negation)
2. Consider which signal you want negated. Hint: the signal name isn't "2".

 

[pathare]

Thank you for your suggestion. I had tried a bitwise not but I tried applying it directly to the 2 it was your suggestion to think about what I was actually applying the not to that did it. It works now : )

 

[degibson]

Thank you for your suggestion. I had tried a bitwise not but I tried applying it directly to the 2 it was your suggestion to think about what I was actually applying the not to that did it. It works now : )

Great! Glad to have helped.