gpsnavidatagen_4ch.v

基于verilog语言的ＧＰＳ模拟源代码

//       000                     000         011                                                                                                  
//       001                     010         010                                                                                                  
//       010                     011         000                                                                                                  
//       011                     010         110                                                                                                  
//       100                     000         111                                                                                                  
//       101                     110         110                                                                                                  
//       110                     111         000                                                                                                  
//       111                     110         010                                                                                                  
                                                                                                                                                  
always @(carr_dco_acc                                                                                                                             
         )                                                                                                                                        
  case(carr_dco_acc[28:25])                                                                                                                       
     0 :begin cos= 3'b011;sin= 3'b001;end                                                                                                         
     1 :begin cos= 3'b010;sin= 3'b010;end                                                                                                         
     2 :begin cos= 3'b001;sin= 3'b011;end                                                                                                         
     3 :begin cos= 3'b000;sin= 3'b011;end                                                                                                         
     4 :begin cos= 3'b101;sin= 3'b011;end                                                                                                         
     5 :begin cos= 3'b110;sin= 3'b010;end                                                                                                         
     6 :begin cos= 3'b111;sin= 3'b001;end                                                                                                         
     7 :begin cos= 3'b111;sin= 3'b000;end                                                                                                         
     8 :begin cos= 3'b111;sin= 3'b101;end                                                                                                         
     9 :begin cos= 3'b110;sin= 3'b110;end                                                                                                         
     10:begin cos= 3'b101;sin= 3'b111;end                                                                                                         
     11:begin cos= 3'b000;sin= 3'b111;end                                                                                                         
     12:begin cos= 3'b001;sin= 3'b111;end                                                                                                         
     13:begin cos= 3'b010;sin= 3'b110;end                                                                                                         
     14:begin cos= 3'b011;sin= 3'b101;end                                                                                                         
     15:begin cos= 3'b011;sin= 3'b000;end                                                                                                         
  endcase                                                                                                                                         
                                                                                                                                                  
                                                                                                                                                  
                                                                                                                                                  
//GPSData after C/A code modulation                                                                                                               
assign out_GPSData = ca_code?({(!cos[2]),cos[1:0]}):(cos) ;                                                                                       
                                                                                                                                                  
                                                                                                                                                  
endmodule                                                                                                                                         
                                                                                                                                                  
                                                                                                                                                 
 


module GPSDataGen_4ch(in_clk, in_Resetn, out_GPSData, a, d, csn, wrn, oen);

input in_clk;                                       
input in_Resetn;                                    
output [2:0] out_GPSData;                           
                                                    
input [15:0]a;                                      
input csn;                                          
input wrn;                                          
input oen;                                          
inout [31:0]d;  

`ifdef DEBUG_NAVI
integer i;
integer j;
`endif                                    
                                                    
                                                    
//the following parameters are SNR, now is not used 
//Now I suggest four sattellite is equal strong     
parameter SNR1=-20  ;                               
parameter SNR2=-30  ;                               
parameter SNR3=-40  ;                               
parameter SNR4=-50  ;                               
`define   K1 = 1E((-SNR1)/20)                       
`define   K2 = 1E((-SNR2)/20)                       
`define   K3 = 1E((-SNR3)/20)                       
`define   K4 = 1E((-SNR4)/20) 

reg [2:0]	Sat1_Subframe_Cnt, Sat2_Subframe_Cnt, Sat3_Subframe_Cnt, Sat4_Subframe_Cnt;
reg [3:0]	Sat1_Word_Cnt, Sat2_Word_Cnt, Sat3_Word_Cnt, Sat4_Word_Cnt;
reg [4:0]	Sat1_NavBit_Cnt, Sat2_NavBit_Cnt, Sat3_NavBit_Cnt, Sat4_NavBit_Cnt;   

reg			NaviData1, NaviData2, NaviData3, NaviData4;

reg [7:0]	Sat1_status, Sat2_status, Sat3_status, Sat4_status;
reg [7:0]	Sat1_nextstatus, Sat2_nextstatus, Sat3_nextstatus, Sat4_nextstatus;

reg 		Sat1_LastWordD29, Sat1_LastWordD30;
reg 		Sat2_LastWordD29, Sat2_LastWordD30;
reg 		Sat3_LastWordD29, Sat3_LastWordD30;
reg 		Sat4_LastWordD29, Sat4_LastWordD30;

reg [23:0]	Sat1_ParityReg, Sat2_ParityReg, Sat3_ParityReg, Sat4_ParityReg;

parameter	IDLE = 8'd0;
parameter	TLMWORD = 8'd1;
parameter	HOWWORD = 8'd2;
parameter	NAVIDATAWORD = 8'd3;
parameter	PARITY = 8'd4;

wire [5:0]	Sat1_PrtW, Sat2_PrtW, Sat3_PrtW, Sat4_PrtW;
wire 		NB1, NB2, NB3, NB4;

wire 		Sat1Prtemp1, Sat1Prtemp2, Sat1Prtemp3;
wire		Sat2Prtemp1, Sat2Prtemp2, Sat2Prtemp3; 
wire 		Sat3Prtemp1, Sat3Prtemp2, Sat3Prtemp3;
wire 		Sat4Prtemp1, Sat4Prtemp2, Sat4Prtemp3;

wire signed [4:0] GPSDataNavi1,GPSDataNavi2,GPSDataNavi3,GPSDataNavi4;                             
wire signed [4:0] out_GPSDataSign;                                                                 
wire [2:0] out_GPSData;                                                                            
wire [2:0] GPSData1;                                                                               
wire [2:0] GPSData2;                                                                               
wire [2:0] GPSData3;                                                                               
wire [2:0] GPSData4;

wire sel1;                                                                                         
wire sel2;                                                                                         
wire sel3;                                                                                         
wire sel4;                                                                                         

assign sel1 = (a == 16'hE100);
assign sel2 = (a == 16'hE200);
assign sel3 = (a == 16'hE300);
assign sel4 = (a == 16'hE400);

//sattilite 1                                                                                      
GPSDataGenSAT_4ch u_1(in_clk, in_Resetn, GPSData1,NB1, sel1, a[7:0], d, csn, wrn, oen);                
                                                                                                   
//sattilite 2                                                                                      
GPSDataGenSAT_4ch u_2(in_clk, in_Resetn, GPSData2,NB2, sel2, a[7:0], d, csn, wrn, oen);                
                                                                                                   
//sattilite 3                                                                                      
GPSDataGenSAT_4ch u_3(in_clk, in_Resetn, GPSData3,NB3, sel3, a[7:0], d, csn, wrn, oen);                
                                                                                                   
//sattilite 4                                                                                      
GPSDataGenSAT_4ch u_4(in_clk, in_Resetn, GPSData4,NB4, sel4, a[7:0], d, csn, wrn, oen);                

assign GPSDataNavi1 = (GPSData1[2]^NaviData1)?(-GPSData1[1:0]):GPSData1[1:0];
assign GPSDataNavi2 = (GPSData2[2]^NaviData2)?(-GPSData2[1:0]):GPSData2[1:0];
assign GPSDataNavi3 = (GPSData3[2]^NaviData3)?(-GPSData3[1:0]):GPSData3[1:0];
assign GPSDataNavi4 = (GPSData4[2]^NaviData4)?(-GPSData4[1:0]):GPSData4[1:0];


assign out_GPSDataSign = GPSDataNavi1 + GPSDataNavi2 + GPSDataNavi3 + GPSDataNavi4;

wire [3:0] temp = (~out_GPSDataSign[3:0]+1'b1);                                                                                                   
assign out_GPSData = out_GPSDataSign[4]? {1'b1,temp[1:0]}:{1'b0,out_GPSDataSign[1:0]};


always @ (posedge in_clk or negedge in_Resetn )
	if (!in_Resetn)
		begin
		 Sat1_NavBit_Cnt <= 5'b0;
		 Sat2_NavBit_Cnt <= 5'b0;
		 Sat3_NavBit_Cnt <= 5'b0;
		 Sat4_NavBit_Cnt <= 5'b0;
		end
	else
		begin
		// satellite 1
		 if ((Sat1_NavBit_Cnt == 29)&& NB1)
		 	Sat1_NavBit_Cnt <= 5'b0;
		 else if (NB1)
		 	Sat1_NavBit_Cnt <= Sat1_NavBit_Cnt + 1;
		// satellite 2 	
		 if ((Sat2_NavBit_Cnt == 29)&& NB2)
		 	Sat2_NavBit_Cnt <= 5'b0;
		 else if (NB2)
		 	Sat2_NavBit_Cnt <= Sat2_NavBit_Cnt + 1;
		// satellite 3 	
		 if ((Sat3_NavBit_Cnt == 29)&& NB3)
		 	Sat3_NavBit_Cnt <= 5'b0;
		 else if (NB3)
		 	Sat3_NavBit_Cnt <= Sat3_NavBit_Cnt + 1;
		// satellite 4 	
		 if ((Sat4_NavBit_Cnt == 29)&& NB4)
		 	Sat4_NavBit_Cnt <= 5'b0;
		 else if (NB4)
		 	Sat4_NavBit_Cnt <= Sat4_NavBit_Cnt + 1;
		 	
		end
   
always @ (posedge in_clk or negedge in_Resetn)
	if (!in_Resetn)
		begin
		 Sat1_Word_Cnt <= 4'b0;
		 Sat2_Word_Cnt <= 4'b0;
		 Sat3_Word_Cnt <= 4'b0;
		 Sat4_Word_Cnt <= 4'b0;
		end
	else
		begin
		 // satellite 1
		 if ((Sat1_Word_Cnt == 9)&&(Sat1_NavBit_Cnt == 29)&& NB1)
		 	Sat1_Word_Cnt <= 4'b0;
		 else if ((Sat1_NavBit_Cnt == 29)&& NB1)
		 	Sat1_Word_Cnt <= Sat1_Word_Cnt + 1;
		 // satellite 2	
		 if ((Sat2_Word_Cnt == 9)&&(Sat2_NavBit_Cnt == 29)&& NB2)
		 	Sat2_Word_Cnt <= 4'b0;
		 else if ((Sat2_NavBit_Cnt == 29)&& NB2)
		 	Sat2_Word_Cnt <= Sat2_Word_Cnt + 1;
		 // satellite 3	
		 if ((Sat3_Word_Cnt == 9)&&(Sat3_NavBit_Cnt == 29)&& NB3)
		 	Sat3_Word_Cnt <= 4'b0;
		 else if ((Sat3_NavBit_Cnt == 29)&& NB3)
		 	Sat3_Word_Cnt <= Sat3_Word_Cnt +1 ;
		 // satellite 4 
		 if ((Sat4_Word_Cnt==9)&&(Sat4_NavBit_Cnt == 29)&& NB4)
		 	Sat4_Word_Cnt <= 4'b0;
		 else if ((Sat4_NavBit_Cnt == 29)&& NB4)	
		 	Sat4_Word_Cnt <= Sat4_Word_Cnt + 1;
		 
		end
		
always @ (posedge in_clk or negedge in_Resetn)
	if (!in_Resetn)
		begin
		 Sat1_Subframe_Cnt <= 3'b0;
		 Sat2_Subframe_Cnt <= 3'b0;
		 Sat3_Subframe_Cnt <= 3'b0;
		 Sat4_Subframe_Cnt <= 3'b0;
		end
	else
		begin
		 // satellite 1
		 if ((Sat1_Subframe_Cnt == 4)&&(Sat1_Word_Cnt == 9)&&(Sat1_NavBit_Cnt == 29)&& NB1)
		 	Sat1_Subframe_Cnt <= 3'b0;
		 else if ((Sat1_Word_Cnt == 9)&&(Sat1_NavBit_Cnt == 29)&& NB1)
		 	Sat1_Subframe_Cnt <= Sat1_Subframe_Cnt + 1;
		 // satellite 2
		 if ((Sat2_Subframe_Cnt == 4)&&(Sat2_Word_Cnt == 9)&&(Sat2_NavBit_Cnt == 29)&& NB2)
		 	Sat2_Subframe_Cnt <= 3'b0;
		 else if((Sat2_Word_Cnt == 9)&&(Sat2_NavBit_Cnt == 29)&& NB2)
		 	Sat2_Subframe_Cnt <= Sat2_Subframe_Cnt + 1;
		 // satellite 3	
		 if ((Sat3_Subframe_Cnt == 4)&&(Sat3_Word_Cnt == 9)&&(Sat3_NavBit_Cnt == 29)&& NB3)
		 	Sat3_Subframe_Cnt <= 3'b0;
		 else if ((Sat3_Word_Cnt == 9)&&(Sat3_NavBit_Cnt == 29)&& NB3)
		 	Sat3_Subframe_Cnt <= Sat3_Subframe_Cnt + 1;
		 // satellite 4
		 if ((Sat4_Subframe_Cnt == 4)&&(Sat4_Word_Cnt==9)&&(Sat4_NavBit_Cnt == 29)&& NB4)
		 	Sat4_Subframe_Cnt <= 3'b0;
		 else if ((Sat4_Word_Cnt==9)&&(Sat4_NavBit_Cnt == 29)&& NB4)
		 	Sat4_Subframe_Cnt <= Sat4_Subframe_Cnt + 1;
		 	
		end


always @ (posedge in_clk or negedge in_Resetn)
	 if (!in_Resetn)
	   begin
	 	Sat1_status <= IDLE;
	 	Sat2_status <= IDLE;
	 	Sat3_status <= IDLE;
	 	Sat4_status <= IDLE;
	   end
	 else