ALU Failing to Load

Posted by Chamkey on Nov 30, 2019; 7:30pm
URL: http://nand2tetris-questions-and-answers-forum.52.s1.nabble.com/ALU-Failing-to-Load-tp4033963.html

Hi guys I'm getting an error trying to load my ALU.
The error I'm getting is:
An internal pin may only be fed once by a parts output...

My Parts are as follows:
    PARTS:
   // Put you code here:

   //Zero the x input
   Mux16(a = x, b[0..15] = false, sel = zx, out = zdx);
   
   //Negate the x input
   Not16(in = x, out = notx);
   Mux16(a = x, b = notx, sel = nx, out = ndx);
   
   //Zero the y input
   Mux16(a = y, b[0..15] = false, sel = zy, out = zdy);
   
   //Negate the y input
   Not16(in = y, out = noty);
   Mux16(a = y, b = noty, sel = ny, out = ndy);
   
   //compute out = x + y (if f = 1) or x & y (if f = 0)
   Or16(a = zdx, b = ndx, out = selx);
   Or16(a = zdy, b = ndy, out = sely);
   Or16(a = selx, b = sely, out = AddXY);
   And16(a = selx, b = sely, out = AndXY);
   Mux16(a = AndXY, b = AddXY, sel = f, out = selXY);
   
   //16-bit output
   Not16(in = selXY, out = nxy);
   Mux16(a = selXY, b = nxy, sel = no, out = c2);
   
   //zr 1 if out == 0
   Or16Way(in = c2, out = c3);
   Not(in = c3, out = zr);
   
   //ng 1 if out < 0
   Splitter16(in = c2, out[1..15] = drop, out[0] = c4);
   Mux16(a = c2, b[0..15] = false, sel = c4, out[0..14] = drop, out[15] = ng);
   
   //finally output
   Or16(in = c2, b[0..15] = false, out = out);

I also built the chip in Logisim so I could visualize the chip. The picture is below.


Please help with this problem.

Edit:
Also I realized I'm getting the wrong outputs. I think my Or16() gates aren't doing a good job. Gonna have to edit and check.