The following diagram is a Mealy machine implementation of the 2's complementer. Implement using one-hot encoding.
module top_module (
input clk,
input areset,
input x,
output z
);
parameter S0 = 1'b0, S1 = 1'b1;
reg current_state,next_state;
always @(*) begin
case(current_state)
S0: next_state = x ? S1 : S0;
S1: next_state = S1;
endcase
end
always @(posedge clk or posedge areset) begin
if(areset)begin
current_state <= S0;
end
else begin
current_state <= next_state;
end
end
assign z = ((current_state == S0) && x) || ((current_state == S1) && ~x);
endmodule
