short_generator.v

基于Xilinx+FPGA的OFDM通信系统基带设计-程序

module SHORT_generator(RESET,FFT_CLK,SHORT_ACK,SHORT_RE,SHORT_IM,SHORT_INDEX,SHORT_DV);
    input RESET;
    input FFT_CLK;
    input SHORT_ACK;
    output [7:0] SHORT_RE;
    output [7:0] SHORT_IM;
    output [7:0] SHORT_INDEX;
    output SHORT_DV;

    reg [7:0] SHORT_RE;
    reg [7:0] SHORT_IM;
    reg [7:0] SHORT_INDEX;
    reg SHORT_DV;

    reg[3:0] i;
    reg[3:0] j;
    reg [7:0] shortrom_re [15:0];
    reg [7:0] shortrom_im [15:0];

always @ (negedge RESET or posedge FFT_CLK)  //registers initial
   if (!RESET)
	begin
     i=0;
     j=0;
     SHORT_RE=0;
     SHORT_IM=0;
     SHORT_INDEX=0;
     SHORT_DV=0;

	shortrom_re[0]=8'b00001100;
	shortrom_re[1]=8'b11011110;
	shortrom_re[2]=8'b11111101;
	shortrom_re[3]=8'b00100100;
	shortrom_re[4]=8'b00011000;
	shortrom_re[5]=8'b00100100;
	shortrom_re[6]=8'b11111101;
	shortrom_re[7]=8'b11011110;
	shortrom_re[8]=8'b00001100;
	shortrom_re[9]=8'b00000001;
	shortrom_re[10]=8'b11101100;
	shortrom_re[11]=8'b11111101;
	shortrom_re[12]=8'b00000000;
	shortrom_re[13]=8'b11111101;
	shortrom_re[14]=8'b11101100;
	shortrom_re[15]=8'b00000001;

	shortrom_im[0]=8'b00001100;
	shortrom_im[1]=8'b00000001;
	shortrom_im[2]=8'b11101100;
	shortrom_im[3]=8'b11111101;
	shortrom_im[4]=8'b00000000;
	shortrom_im[5]=8'b11111101;
	shortrom_im[6]=8'b11101100;
	shortrom_im[7]=8'b00000001;
	shortrom_im[8]=8'b00001100;
	shortrom_im[9]=8'b11011110;
	shortrom_im[10]=8'b11111101;
	shortrom_im[11]=8'b00100100;
	shortrom_im[12]=8'b00011000;
	shortrom_im[13]=8'b00100100;
	shortrom_im[14]=8'b11111101;
	shortrom_im[15]=8'b11011110;

     end


//************************************

else
  begin
  if (SHORT_ACK)
    if (i<=9)
      if(j<15)
	   begin
	   SHORT_RE=shortrom_re[j];
	   SHORT_IM=shortrom_im[j];
	   SHORT_DV=1;
          if(i==0&j==0)   //multiplied by the window function
            begin
            SHORT_RE=SHORT_RE>>1;
            SHORT_IM=SHORT_IM>>1;
            end
        j=j+1;
	   SHORT_INDEX=SHORT_INDEX+1;
	   end
	 else
	   begin
	   SHORT_RE=shortrom_re[j];
	   SHORT_IM=shortrom_im[j];
	   SHORT_INDEX=SHORT_INDEX+1;
	   SHORT_DV=1;
	   j=0;
	   i=i+1;
	   end
    else
      begin
      i=0;
	 SHORT_RE=shortrom_re[j]>>1;  //multiplied by the window function
	 SHORT_IM=shortrom_im[j]>>1;
	 SHORT_INDEX=SHORT_INDEX+1;
	 end
  else
    begin
    i=0;
    j=0;
    SHORT_RE=0;
    SHORT_IM=0;
    SHORT_INDEX=0;
    SHORT_DV=0;
    end
  end
  

endmodule