module SUMATOR_PROPAGAT_8_BIT(cin,cout,s,x,y);

	input cin;
	input  x;
	input  y;
	output reg cout;
	output reg s;
	always @(x or y) begin
		{cout,s}=x+y+cin;
	end
endmodule

module TEST_SUMATOR_PROPAGAT_8_BIT;
	reg cin;
	reg [7:0] x;
	reg [7:0] y;
	wire[7:0] s;
	wire cout;
	wire c01, c12, c23, c34, c45, c56, c67;
	TEST_SUMATOR_PROPAGAT_8_BIT zero(.cin(cin),.cout(c01),.s(s[0]),.x(x[0]),.y(y[0]));
	TEST_SUMATOR_PROPAGAT_8_BIT unu(.cin(c01),.cout(c12),.s(s[1]),.x(x[1]),.y(y[1]));
	TEST_SUMATOR_PROPAGAT_8_BIT doi(.cin(c12),.cout(c23),.s(s[2]),.x(x[2]),.y(y[2]));
	TEST_SUMATOR_PROPAGAT_8_BIT trei(.cin(c23),.cout(c34),.s(s[3]),.x(x[3]),.y(y[3]));
	TEST_SUMATOR_PROPAGAT_8_BIT patru(.cin(c34),.cout(c45),.s(s[4]),.x(x[4]),.y(y[4]));
	TEST_SUMATOR_PROPAGAT_8_BIT cinci(.cin(c45),.cout(c56),.s(s[5]),.x(x[5]),.y(y[5]));
	TEST_SUMATOR_PROPAGAT_8_BIT sase(.cin(c56),.cout(c67),.s(s[6]),.x(x[6]),.y(y[6]));
	TEST_SUMATOR_PROPAGAT_8_BIT sapte(.cin(c67),.cout(cout),.s(s[7]),.x(x[7]),.y(y[7]));

	initial begin
		#5 cin=1'b0;x=8'h20;y=8'h30;
		#5 cin=0'b0;x=8'h25;y=8'h30;
		#5 cin=0'b0;x=8'h36;y=8'h75;
		#5 cin=0'b0;x=8'h54;y=8'h43;
		#5 cin=0'b0;x=8'h42;y=8'h34;
		#5 cin=0'b0;x=8'h86;y=8'h76;
		#5 cin=0'b0;x=8'h43;y=8'h56;
		#5 cin=0'b0;x=8'h76;y=8'h24;
	#5 $finish;
	end
endmodule