Flash_bounder.v

module Flash_bounder(clk, rst_n, flick, LED);



input clk, rst_n,flick;

output [15:0]LED;


wire clk, rst_n, flick;

reg [15:0]LED;

reg [1:0]operation;

integer N;

integer i;

//operation mode
parameter IDLE 		  =  2'b00;
parameter UP			  =  2'B01;
parameter DOWN 		  =  2'b10;
parameter KICK_BACK	  =  2'b11;



//States
parameter INIT         =  6'b000001;
parameter ZERO_TO_FIVE =  6'b000010;
parameter OFF_TO_ZERO  =  6'b000100;
parameter ZERO_TO_TEN  =  6'b001000;
parameter OFF_TO_FOUR  =  6'b010000;
parameter FOUR_TO_FTEEN = 6'B100000;



parameter SIZE         =  6        ;

reg [SIZE - 1: 0] state;

reg [SIZE - 1: 0]	next_state;


// Change state block

always @(posedge clk or negedge rst_n)
begin

	if(!rst_n) begin
	
		state <=  INIT;
			
	end
	
	else begin
	
		state <= next_state;
		
	end

end




// Operation on N block

always @(posedge clk or negedge rst_n)
begin
	
	if(!rst_n) begin
	
		N <= -1;
	
	end
	
	else begin
	
		if(operation == UP) begin
		
			N <= N + 1;
		
		end
		
		else if(operation == IDLE) begin
		
			N <= N;
		
		end
		
		else begin
		
			N <= N - 1;
		
		end
		
	
	end



end




//FSM block


always @(state or operation)
begin

	case(state)
	
	INIT: begin
	
		if(operation == UP) begin
			
			next_state = ZERO_TO_FIVE;
			
		end
		
		else begin
		
			next_state = INIT;
		
		end
		
	
	end
	
	
	ZERO_TO_FIVE: begin
	
		if(operation == UP) begin
		
		
			next_state = ZERO_TO_FIVE;
		
		end
	
		else begin
		
			next_state = OFF_TO_ZERO;
		
		end
	
	end
	
	
	OFF_TO_ZERO: begin
	
		if(operation == DOWN) begin
		
			next_state = OFF_TO_ZERO;
		
		end
		
		else begin
		
			next_state = ZERO_TO_TEN;
		
		end
	
	end
	
	
	ZERO_TO_TEN: begin
	
		if(operation == KICK_BACK) begin
		
			next_state = OFF_TO_ZERO;
		
		end
		
		
		else if(operation == DOWN) begin
		
			next_state = OFF_TO_FOUR;
		
		end
		
		
		else begin
		
			next_state = ZERO_TO_TEN;
		
		end
		
		
	end
	
	
	OFF_TO_FOUR: begin
	
	
		if(operation == DOWN) begin
		
			next_state = OFF_TO_FOUR;
		
		end
		
		
		else begin
		
			next_state = FOUR_TO_FTEEN;
		
		end
		
	
	
	end
	
	
	FOUR_TO_FTEEN: begin
	
	
		if(operation == KICK_BACK) begin
		
			next_state = OFF_TO_FOUR;
	
		end
		
		
		else if(operation == DOWN) begin
		
			next_state = INIT;
				
		end
		
		else begin
		
			next_state = FOUR_TO_FTEEN;
		
		end
		
	
	end
	
	
	default: next_state = INIT;
	
	endcase

end




//Logic block

always @(state or flick or N) begin

	operation = 2'b00;


	case(state)
	
	
	INIT: begin
	
		if(N >= 0) operation = DOWN;
		
		else if(flick) operation = UP;
		
		else operation = IDLE;
		
	
	end
	
	
	ZERO_TO_FIVE: begin
	
		if(N < 5) operation = UP;
		
		else operation = DOWN;
	
	end
	
	
	OFF_TO_ZERO: begin
	
		if(N >= 0) operation = DOWN;
		
		else operation = UP;
	
	end
	
	
	ZERO_TO_TEN: begin
	
		if(flick && (N == 5 || N == 10)) operation = KICK_BACK;
		
		else if(N == 10) operation = DOWN;
		
		else operation = UP;
		
	end
	
	
	OFF_TO_FOUR: begin
	
		if(N > 4) operation = DOWN;
		
		else operation = UP;
	
	end
	
	
	FOUR_TO_FTEEN: begin
	
		if(flick && (N == 5 || N == 10)) operation = KICK_BACK;
		
		else if(N == 15) operation = DOWN;
		
		else operation = UP;
		
	end
	
	
	default: operation = IDLE;
	
	
	endcase
	
end




//Decode block


always @(N)
begin

	if(N == -1) 
		for(i = 0; i < 16 ; i = i + 1)
		begin
		
			LED[i] = 0;
		
		end
	

	else
	
		for( i = 0; i < 16 ; i = i + 1)
		begin
			
			if(i <= N) LED[i] = 1'b1;
			
			else LED[i] = 1'b0;
			
		end
	
end

endmodule