fpga/hi_sniffer.v

   1 //-----------------------------------------------------------------------------
   2 // Copyright (C) Proxmark3 contributors. See AUTHORS.md for details.
   3 //
   4 // This program is free software: you can redistribute it and/or modify
   5 // it under the terms of the GNU General Public License as published by
   6 // the Free Software Foundation, either version 3 of the License, or
   7 // (at your option) any later version.
   8 //
   9 // This program is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13 //
  14 // See LICENSE.txt for the text of the license.
  15 //-----------------------------------------------------------------------------
  16
  17 module hi_sniffer(
  18     input ck_1356meg,
  19     input [7:0] adc_d,
  20
  21     output ssp_din,
  22     output reg ssp_frame,
  23     output ssp_clk,
  24     output adc_clk,
  25     output pwr_lo,
  26     output pwr_hi,
  27     output pwr_oe1,
  28     output pwr_oe2,
  29     output pwr_oe3,
  30     output pwr_oe4
  31 );
  32
  33 // We are only snooping, all off.
  34 assign pwr_hi  = 1'b0;
  35 assign pwr_lo  = 1'b0;
  36 assign pwr_oe1 = 1'b0;
  37 assign pwr_oe2 = 1'b0;
  38 assign pwr_oe3 = 1'b0;
  39 assign pwr_oe4 = 1'b0;
  40
  41 //reg ssp_frame;
  42 reg [7:0] adc_d_out = 8'd0;
  43 reg [2:0] ssp_cnt   = 3'd0;
  44
  45 assign adc_clk =  ck_1356meg;
  46 assign ssp_clk = ~ck_1356meg;
  47 assign ssp_din = adc_d_out[0];
  48
  49 always @(posedge ssp_clk)
  50 begin
  51     ssp_cnt <= ssp_cnt + 1;
  52
  53     if(ssp_cnt[2:0] == 3'b000) // set frame length
  54     begin
  55         adc_d_out[7:0] <= adc_d;
  56         ssp_frame <= 1'b1;
  57     end
  58     else
  59     begin
  60         // shift value right one bit
  61         adc_d_out[7:0] <= {1'b0, adc_d_out[7:1]};
  62         ssp_frame <= 1'b0;
  63     end
  64
  65 end
  66 endmodule