DE10_LITE_Golden_Top.v

// ============================================================================
//   Ver  :| Author					:| Mod. Date :| Changes Made:
//   V1.1 :| Alexandra Du			:| 06/01/2016:| Added Verilog file
// ============================================================================


//=======================================================
//  This code is generated by Terasic System Builder
//=======================================================

`define ENABLE_ADC_CLOCK
`define ENABLE_CLOCK1
`define ENABLE_CLOCK2
`define ENABLE_SDRAM
`define ENABLE_HEX0
`define ENABLE_HEX1
`define ENABLE_HEX2
`define ENABLE_HEX3
`define ENABLE_HEX4
`define ENABLE_HEX5
`define ENABLE_KEY
`define ENABLE_LED
`define ENABLE_SW
`define ENABLE_VGA
`define ENABLE_ACCELEROMETER
`define ENABLE_ARDUINO
`define ENABLE_GPIO

module DE10_LITE_Golden_Top(

	//////////// ADC CLOCK: 3.3-V LVTTL //////////
`ifdef ENABLE_ADC_CLOCK
	input 		          		ADC_CLK_10,
`endif
	//////////// CLOCK 1: 3.3-V LVTTL //////////
`ifdef ENABLE_CLOCK1
	input 		          		MAX10_CLK1_50,
`endif
	//////////// CLOCK 2: 3.3-V LVTTL //////////
`ifdef ENABLE_CLOCK2
	input 		          		MAX10_CLK2_50,
`endif

	//////////// SDRAM: 3.3-V LVTTL //////////
`ifdef ENABLE_SDRAM
	output		    [12:0]		DRAM_ADDR,
	output		     [1:0]		DRAM_BA,
	output		          		DRAM_CAS_N,
	output		          		DRAM_CKE,
	output		          		DRAM_CLK,
	output		          		DRAM_CS_N,
	inout 		    [15:0]		DRAM_DQ,
	output		          		DRAM_LDQM,
	output		          		DRAM_RAS_N,
	output		          		DRAM_UDQM,
	output		          		DRAM_WE_N,
`endif

	//////////// SEG7: 3.3-V LVTTL //////////
`ifdef ENABLE_HEX0
	output		     [7:0]		HEX0,
`endif
`ifdef ENABLE_HEX1
	output		     [7:0]		HEX1,
`endif
`ifdef ENABLE_HEX2
	output		     [7:0]		HEX2,
`endif
`ifdef ENABLE_HEX3
	output 		     [7:0]		HEX3,
`endif
`ifdef ENABLE_HEX4
	output		     [7:0]		HEX4,
`endif
`ifdef ENABLE_HEX5
	output		     [7:0]		HEX5,
`endif

	//////////// KEY: 3.3 V SCHMITT TRIGGER //////////
`ifdef ENABLE_KEY
	input 		     [1:0]		KEY,
`endif

	//////////// LED: 3.3-V LVTTL //////////
`ifdef ENABLE_LED
	output		     [9:0]		LEDR,
`endif

	//////////// SW: 3.3-V LVTTL //////////
`ifdef ENABLE_SW
	input 		     [9:0]		SW,
`endif

	//////////// VGA: 3.3-V LVTTL //////////
`ifdef ENABLE_VGA
	output		     [3:0]		VGA_B,
	output		     [3:0]		VGA_G,
	output		          		VGA_HS,
	output		     [3:0]		VGA_R,
	output		          		VGA_VS,
`endif

	//////////// Accelerometer: 3.3-V LVTTL //////////
`ifdef ENABLE_ACCELEROMETER
	output		          		GSENSOR_CS_N,
	input 		     [2:1]		GSENSOR_INT,
	output		          		GSENSOR_SCLK,
	inout 		          		GSENSOR_SDI,
	inout 		          		GSENSOR_SDO,
`endif

	//////////// Arduino: 3.3-V LVTTL //////////
`ifdef ENABLE_ARDUINO
	inout 		    [15:0]		ARDUINO_IO,
	inout 		          		ARDUINO_RESET_N,
`endif

	//////////// GPIO, GPIO connect to GPIO Default: 3.3-V LVTTL //////////
`ifdef ENABLE_GPIO
	inout 		    [35:0]		GPIO
`endif
);

reg [7:0] txData;
reg txLoad  = 1'b0;
wire [7:0] rxData;
reg flag = 1'b1;

wire txReset = 1'b1;
wire rxReset = 1'b1;
reg [3:0] hex_info [5:0];
wire txIdle;
wire txReady;
wire rxIdle;
wire rxReady;

parameter ClkFrequency = 50000000;
parameter Baud = 9600;

wire RxD_data_ready;
wire [7:0] RxD_data;
async_receiver GPS(	.clk(MAX10_CLK1_50), 
							.rst(1'b0), 
							.RxD(GPIO[35]), 							
							.RxD_data_ready(rxReady), 
							.RxD_data(rxData));	
							
defparam GPS.ClkFrequency=ClkFrequency;
defparam GPS.Baud=Baud;
	  
hex7seg h0(LAT[3:0], HEX0);
hex7seg h1(LAT[11:8], HEX1);
hex7seg h2(LAT[19:16], HEX2);
hex7seg h3(LON[3:0], HEX3);
hex7seg h4(LON[11:8], HEX4);
hex7seg h5(LON[19:16], HEX5);

integer precision = 3;
reg [2:0] STATE=0;
reg [23:0] NMEA=0;
reg [23:0] LAT=0;
reg [23:0] LON=0;

integer prec_cnt = 0;
always @(posedge MAX10_CLK1_50) begin		
	case(STATE)
		0: begin //Search for '$'		
			if(rxReady && rxData=="$")begin// '$': Start of frame	
				STATE<=STATE+1;				
			end
		end
		1: begin //Check Tag, if not the proper tag go back
			if(rxReady) begin				
				if(rxData==",")begin
					if(NMEA=="GLL")begin 
						STATE<=STATE+1;
					end
					else begin
						STATE<=0;
					end
				end
				else begin //Grab the NMEA Message Type		
					NMEA[23:8]<=NMEA[15:0];
					NMEA[7:0]<=rxData; //Grab the tag info						
				end	
			end				
		end
		2: begin //Parse the latitude 	
			if(rxReady) begin
				if(rxData==",")begin
					STATE<=STATE+1;
					prec_cnt = 0;
				end
				else if (prec_cnt < precision) begin //grab only 3 first LAT values, because we have only 3 HEX available
					prec_cnt = prec_cnt + 1;
					LAT[23:8]<=LAT[15:0];
					LAT[7:0]<=rxData; 
				end	
			end
		end	
		3: begin //Parse letter
			if(rxReady) begin
				if(rxData==",")begin
					STATE<=STATE+1;
				end
			end
		end	
		4: begin //Parse the longitude		
			if(rxReady) begin
				if(rxData==10)begin //LF: Line Feed, end of message, go to idle state				
					STATE<=0;
					prec_cnt = 0;
				end	
				else if (prec_cnt < precision)begin //grab only 3 first LON values, because we have only 3 HEX available
					prec_cnt = prec_cnt + 1;
					LON[23:8]<=LON[15:0];
					LON[7:0]<=rxData;					
				end	
			end
		end
		default: begin
			STATE<=0;
		end
	endcase
end

//just for debug
assign LEDR[0] = STATE[0];
assign LEDR[1] = STATE[1];

endmodule