Shema

`timescale 1ns / 1ps
module EightToThreeCoder(
input x1,
input x2,
input x3,
input x4,
input x5,
input x6,
input x7,
output y2,
output y1,
output y0
    );
wire not_x1, not_x2, not_x3, not_x4, not_x5, not_x6, not_x7, x76,
not_x76, x54, not_x54, x32, not_x32, x75, not_x75, x31, not_x31;
nand(not_x1, x1,x1);
nand(not_x2, x2,x2);
nand(not_x3, x3,x3);
nand(not_x4, x4,x4);
nand(not_x5, x5,x5);
nand(not_x6, x6, x6);
nand(not_x7, x7,x7);

nand(x76,not_x7,not_x6);
nand(not_x76, x76, x76);
nand(x54, not_x5, not_x4);
nand(not_x54, x54, x54);
nand(y2, not_x76, not_x54);

nand(x32, not_x3, not_x2);
nand(not_x32, x32, x32);
nand(y1, not_x76, not_x32);

nand(x75, not_x7, not_x5);
nand(not_x75, x75, x75);
nand(x31, not_x3, not_x1);
nand(not_x31, x31, x31);
nand(y0, not_x75, not_x31);

endmodule