Модуль получает компоненту цвета, от 0 до 63 и выдает либо 0, либо 1 - ближайший цвет.
1module dither
2(
3    input  wire [5:0] orgclr, // 0..63
4    output wire       result  // 0 или 1
5);
6
7assign result = (orgclr + color[5:0] >= 32);
8
9reg [ 5:0] color;
10
11always @(*) begin
12case ({Ya[3:1], Xa[3:1]})
13
14    // 0
15    6'b000_000: color = 0;
16    6'b000_001: color = 32;
17    6'b000_010: color = 8;
18    6'b000_011: color = 40;
19    6'b000_100: color = 2;
20    6'b000_101: color = 34;
21    6'b000_110: color = 10;
22    6'b000_111: color = 42;
23    // 1
24    6'b001_000: color = 48;
25    6'b001_001: color = 16;
26    6'b001_010: color = 56;
27    6'b001_011: color = 24;
28    6'b001_100: color = 50;
29    6'b001_101: color = 18;
30    6'b001_110: color = 58;
31    6'b001_111: color = 26;
32    // 2
33    6'b010_000: color = 12;
34    6'b010_001: color = 44;
35    6'b010_010: color = 4;
36    6'b010_011: color = 36;
37    6'b010_100: color = 14;
38    6'b010_101: color = 46;
39    6'b010_110: color = 6;
40    6'b010_111: color = 38;
41    // 3
42    6'b011_000: color = 60;
43    6'b011_001: color = 28;
44    6'b011_010: color = 52;
45    6'b011_011: color = 20;
46    6'b011_100: color = 62;
47    6'b011_101: color = 30;
48    6'b011_110: color = 54;
49    6'b011_111: color = 22;
50    // 4
51    6'b100_000: color = 3;
52    6'b100_001: color = 35;
53    6'b100_010: color = 11;
54    6'b100_011: color = 43;
55    6'b100_100: color = 1;
56    6'b100_101: color = 33;
57    6'b100_110: color = 9;
58    6'b100_111: color = 41;
59    // 5
60    6'b101_000: color = 51;
61    6'b101_001: color = 19;
62    6'b101_010: color = 59;
63    6'b101_011: color = 27;
64    6'b101_100: color = 49;
65    6'b101_101: color = 17;
66    6'b101_110: color = 57;
67    6'b101_111: color = 25;
68    // 6
69    6'b110_000: color = 15;
70    6'b110_001: color = 47;
71    6'b110_010: color = 7;
72    6'b110_011: color = 39;
73    6'b110_100: color = 13;
74    6'b110_101: color = 45;
75    6'b110_110: color = 5;
76    6'b110_111: color = 37;
77    // 7
78    6'b111_000: color = 63;
79    6'b111_001: color = 31;
80    6'b111_010: color = 55;
81    6'b111_011: color = 23;
82    6'b111_100: color = 61;
83    6'b111_101: color = 29;
84    6'b111_110: color = 53;
85    6'b111_111: color = 21;
86
87endcase
88end