myfx2.v

FPGA与USB通信的测试代码

module MYFX2 (
              nRESET,	PA, GPD,GPA , CTL,RDY,USER, // Inputs from FX2
              IFCLK,CLKOUT, nINT5,// Inputs from FX2

			   USBCLK,		// Output to FX2		  
		       MMCLK,       //from cytal
     		   LED,		    // LED indicator
               KEY,
               RAMAA,RAMAD,RAMAUB,RAMALB,RAMAWE,RAMACE,RAMAOE,
               RAMBA,RAMBD,RAMBUB,RAMBLB,RAMBWE,RAMBCE,RAMBOE
              );
//////////////////////////////////
output [17:0]RAMAA;
output [17:0]RAMBA;
inout  [15:0]RAMAD;
inout  [15:0]RAMBD;
output RAMAUB,RAMALB,RAMAWE,RAMACE,RAMAOE;
output RAMBUB,RAMBLB,RAMBWE,RAMBCE,RAMBOE;
////////////////////////////////////////////
input nRESET;
///////////////////////////////////
input [7:0]PA;
inout [15:0]GPD;
input [8:0]GPA;
input [5:0]CTL;
input [5:0]RDY;
input [5:0]USER;
input IFCLK,CLKOUT, nINT5;
//////////////////////////////////

input MMCLK;
input [2:0]KEY;

output  [3:0]LED;
//reg [3:0]LED;
wire      clk_r;
reg[23:0] Mega_cnt;
reg       dir;
reg       LDT;
output  USBCLK;


assign USBCLK=MMCLK;
assign GPD[2:0]=KEY[2:0];
//assign GPD[1]=KEY[1];
//assign GPD[2]=KEY[2];
assign LED[2:0]=PA[2:0];







/**********Get a Slow Clock********/
always @(posedge MMCLK or negedge nRESET)
begin
if(!nRESET)
  begin
  Mega_cnt<=0;
  end
else
  begin
  Mega_cnt<=Mega_cnt+1;
  end
end

assign clk_r = Mega_cnt[23];
/**********************************/


always @(posedge clk_r or negedge nRESET)
begin
  if(!nRESET)
     begin
    // LED <= 4'b1;
     dir <= 'b0;
     end
 else  
 
    LDT<=~LDT;
end

assign LED[3]=LDT;



												
endmodule