Grouped the gates and corrected xnor16.v nor16.v (#6)

Alright!

gates/demux/demux.v

@@ -0,0 +1,9 @@
+module demux(y, z, a, sel);
+    input a, sel;
+    output y, z;
+    wire notSel;
+
+    not(notSel, sel);
+    and(z, a, sel);
+    and(y, a, notSel);
+endmodule

gates/demux/demux16.v

@@ -0,0 +1,23 @@
+module demux16(y16, z16, a16, sel);
+    input [15:0] a16;
+    input [15:0] z16;
+    input [1:0] sel;
+    output [15:0] y16;
+
+    demux(y16[0],  z16[0],  a16[0],  sel);
+    demux(y16[1],  z16[1],  a16[1],  sel);
+    demux(y16[2],  z16[2],  a16[2],  sel);
+    demux(y16[3],  z16[3],  a16[3],  sel);
+    demux(y16[4],  za16[4], a16[4],  sel);
+    demux(y16[5],  z16[5],  a16[5],  sel);
+    demux(y16[6],  z16[6],  a16[6],  sel);
+    demux(y16[7],  z16[7],  a16[7],  sel);
+    demux(y16[8],  z16[8],  a16[8],  sel);
+    demux(y16[9],  z16[9],  a16[9],  sel);
+    demux(y16[10], z16[10], a16[10], sel);
+    demux(y16[11], z16[11], a16[11], sel);
+    demux(y16[12], z16[12], a16[12], sel);
+    demux(y16[13], z16[13], a16[13], sel);
+    demux(y16[14], z16[14], a16[14], sel);
+    demux(y16[15], z16[15], a16[15], sel);
+endmodule

gates/demux/demux4way.v

@@ -0,0 +1,13 @@
+'include "demux.v"
+
+module demux4way(out0, out1, out2, out3, i0, i1, sel);
+    input i0, i1;
+    input [1:0] sel;
+    output out0, out1, out2, out3;
+
+    wire [1:0] [1:0] sel0 = sel;
+    wire [0:1] [1:0] sel1 = sel;
+
+    demux(out0, out1, i0, sel0);
+    demux(out2, out3, i1, sel1);
+endmodule

gates/demux/demux4way16.v

@@ -0,0 +1,22 @@
+'include "demux.v"
+
+module demux4way(out0, out1, out2, out3, i0, i1, sel);
+    input [15:0]i0;
+    input [15:0]i1;
+    input [3:0]sel;
+    output [15:0]out0;
+    output [15:0]out1;
+    output [15:0]out2;
+    output [15:0]out3;
+
+    wire [3:0] [1:0] sel0 = sel;
+    wire [0:3] [1:0] sel1 = sel;
+
+    not(notSel0, sel0);
+    not(notSel1, sel1);
+
+    and(out1, i0, sel0);
+    and(out0, i0, notSel0);
+    and(out2, i1, sel1);
+    and(out3, i1, notSel1);
+endmodule

gates/demux/demux8way.v

@@ -0,0 +1,13 @@
+'include "demux4way.v"
+
+module demux8way(out0, out1, out3, out4, out5, out6, out7, i0, i1, i2, i3, sel);
+    input i0, i1, i2, i3;
+    input [7:0]sel;
+    output out0, out1, out2, out3, out4, out5, out6, out7;
+
+    wire [7:0] [3:0] sel0 = sel;
+    wire [0:7] [3:0] sel1 = sel;
+
+    demux4way (out0 ,out1, out2, out3, i0, i1, sel0);
+    demux4way (out4, out5, out6, out7, i2, i3, sel1);
+endmodule

gates/demux/demux8way16.v

@@ -0,0 +1,23 @@
+'include "demux4way16.v"
+
+module demux8way(out0, out1, out3, out4, out5, out6, out7, i0, i1, i2, i3, sel);
+    input [15:0]i0;
+    input [15:0]i1;
+    input [15:0]i2;
+    input [15:0]i3;
+    input [7:0]sel;
+    output [15:0]out0;
+    output [15:0]out1;
+    output [15:0]out2;
+    output [15:0]out3;
+    output [15:0]out4;
+    output [15:0]out5;
+    output [15:0]out6;
+    output [15:0]out7;
+
+    wire [7:0] [3:0] sel0 = sel;
+    wire [0:7] [3:0] sel1 = sel;
+
+    demux4way16(out0 ,out1, out2, out3, i0, i1, sel0);
+    demux4way16(out4, out5, out6, out7, i2, i3, sel1);
+endmodule