TrafficLightController.v

module TrafficLight(input clk, //LED_NS represent the North-South LEDs
		    input rst, //LED_WE represent the West-East LEDs
		    output reg [2:0] LED_NS, LED_WE);
/*Let 100 = Red
      010 = Yellow
      001 = Green 
We have 6 different states, defining them below */

parameter S0 = 6'b000001,   //When NS is green and EW is red
	  S1 = 6'b000010,   //When NS is yellow and EW is red
	  S2 = 6'b000100,   //When NS is red and EW is red
	  S3 = 6'b001000,   //When NS is red and EW is green
	  S4 = 6'b010000,   //When NS is red and EW is yellow
	  S5 = 6'b100000;   //When NS is red and EW is red
//Then the cycle repeats

reg [5:0] state;
reg [3:0] count;

//Defining transition of states
always@(posedge clk or posedge rst)
begin
if(rst) begin    //Active HIGH reset
state <= S0;
count <= 0; end
else 
begin
case(state)
S0: begin 
	if(count == 4'd14)
	begin count <= 0;
	state <= S1; end
	else begin 
	count = count + 1; state <= S0; end end
S1: begin 
	if(count == 4'd2)
	begin count <= 0;
	state <= S2; end
	else begin 
	count = count + 1; state <= S1; end end
S2: begin 
	if(count == 4'd2)
	begin count <= 0;
	state <= S3; end
	else begin 
	count = count + 1; state <= S2; end end
S3: begin 
	if(count == 4'd14)
	begin count <= 0;
	state <= S4; end
	else begin 
	count = count + 1; state <= S3; end end
S4: begin 
	if(count == 4'd2)
	begin count <= 0;
	state <= S5; end
	else begin 
	count = count + 1; state <= S4; end end
S5: begin 
	if(count == 4'd2)
	begin count <= 0;
	state <= S0; end
	else begin 
	count = count + 1; state <= S5; end end
endcase
end
end
/*    100 = Red
      010 = Yellow
      001 = Green     */

//Output of LEDs//

always@(*)
begin
case(state) 
S0: begin LED_NS = 3'b001;  LED_WE = 3'b100; end
S1: begin LED_NS = 3'b010;  LED_WE = 3'b100; end
S2: begin LED_NS = 3'b100;  LED_WE = 3'b100; end
S3: begin LED_NS = 3'b100;  LED_WE = 3'b001; end
S4: begin LED_NS = 3'b100;  LED_WE = 3'b010; end
S5: begin LED_NS = 3'b100;  LED_WE = 3'b100; end
endcase
end

endmodule