Arithmetic circuits- 8bit adder

8 BIT ADDER

module adder8bit1(carry,sum,a,b,ci);
output carry;
output [7:0]sum;
input [7:0]a,b;
input ci;
reg [7:0]sum;
reg carry;
reg [8:0]tmp;
always @(a,b,ci)
begin
assign tmp=a+b+ci;
assign sum=tmp[7:0];
assign carry=tmp[8];
end
endmodule