X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/c2ca50419d360dc80196fba5a4e39c33ef4d1a97..5ea2a24839c71ba6e58af937a392a6204b8b4696:/fpga/hi_read_rx_xcorr.v diff --git a/fpga/hi_read_rx_xcorr.v b/fpga/hi_read_rx_xcorr.v deleted file mode 100644 index 80e36327..00000000 --- a/fpga/hi_read_rx_xcorr.v +++ /dev/null @@ -1,170 +0,0 @@ -//----------------------------------------------------------------------------- -// -// Jonathan Westhues, April 2006 -//----------------------------------------------------------------------------- - -module hi_read_rx_xcorr( - pck0, ck_1356meg, ck_1356megb, - pwr_lo, pwr_hi, pwr_oe1, pwr_oe2, pwr_oe3, pwr_oe4, - adc_d, adc_clk, - ssp_frame, ssp_din, ssp_dout, ssp_clk, - cross_hi, cross_lo, - dbg, - xcorr_is_848, snoop -); - input pck0, ck_1356meg, ck_1356megb; - output pwr_lo, pwr_hi, pwr_oe1, pwr_oe2, pwr_oe3, pwr_oe4; - input [7:0] adc_d; - output adc_clk; - input ssp_dout; - output ssp_frame, ssp_din, ssp_clk; - input cross_hi, cross_lo; - output dbg; - input xcorr_is_848, snoop; - -// Carrier is steady on through this, unless we're snooping. -assign pwr_hi = ck_1356megb & (~snoop); -assign pwr_oe1 = 1'b0; -assign pwr_oe3 = 1'b0; -assign pwr_oe4 = 1'b0; - -// Clock divider -reg [0:0] fc_divider; -always @(negedge ck_1356megb) - fc_divider <= fc_divider + 1; -wire fc_div2 = fc_divider[0]; - -reg adc_clk; -always @(ck_1356megb) - if (xcorr_is_848) - adc_clk <= ck_1356megb; - else - adc_clk <= fc_div2; - -// When we're a reader, we just need to do the BPSK demod; but when we're an -// eavesdropper, we also need to pick out the commands sent by the reader, -// using AM. Do this the same way that we do it for the simulated tag. -reg after_hysteresis, after_hysteresis_prev, after_hysteresis_prev_prev; -reg [11:0] has_been_low_for; -always @(negedge adc_clk) -begin - if(& adc_d[7:0]) after_hysteresis <= 1'b1; - else if(~(| adc_d[7:0])) after_hysteresis <= 1'b0; - - if(after_hysteresis) - begin - has_been_low_for <= 7'b0; - end - else - begin - if(has_been_low_for == 12'd4095) - begin - has_been_low_for <= 12'd0; - after_hysteresis <= 1'b1; - end - else - has_been_low_for <= has_been_low_for + 1; - end -end - -// Let us report a correlation every 4 subcarrier cycles, or 4*16 samples, -// so we need a 6-bit counter. -reg [5:0] corr_i_cnt; -// And a couple of registers in which to accumulate the correlations. -// we would add at most 32 times adc_d, the result can be held in 13 bits. -// Need one additional bit because it can be negative as well -reg signed [13:0] corr_i_accum; -reg signed [13:0] corr_q_accum; -reg signed [7:0] corr_i_out; -reg signed [7:0] corr_q_out; -// clock and frame signal for communication to ARM -reg ssp_clk; -reg ssp_frame; - - -always @(negedge adc_clk) -begin - corr_i_cnt <= corr_i_cnt + 1; -end - - -// ADC data appears on the rising edge, so sample it on the falling edge -always @(negedge adc_clk) -begin - // These are the correlators: we correlate against in-phase and quadrature - // versions of our reference signal, and keep the (signed) result to - // send out later over the SSP. - if(corr_i_cnt == 6'd0) - begin - if(snoop) - begin - // Send only 7 most significant bits of tag signal (signed), LSB is reader signal: - corr_i_out <= {corr_i_accum[13:7], after_hysteresis_prev_prev}; - corr_q_out <= {corr_q_accum[13:7], after_hysteresis_prev}; - after_hysteresis_prev_prev <= after_hysteresis; - end - else - begin - // 8 most significant bits of tag signal - corr_i_out <= corr_i_accum[13:6]; - corr_q_out <= corr_q_accum[13:6]; - end - - corr_i_accum <= adc_d; - corr_q_accum <= adc_d; - end - else - begin - if(corr_i_cnt[3]) - corr_i_accum <= corr_i_accum - adc_d; - else - corr_i_accum <= corr_i_accum + adc_d; - - if(corr_i_cnt[3] == corr_i_cnt[2]) // phase shifted by pi/2 - corr_q_accum <= corr_q_accum + adc_d; - else - corr_q_accum <= corr_q_accum - adc_d; - - end - - // The logic in hi_simulate.v reports 4 samples per bit. We report two - // (I, Q) pairs per bit, so we should do 2 samples per pair. - if(corr_i_cnt == 6'd32) - after_hysteresis_prev <= after_hysteresis; - - // Then the result from last time is serialized and send out to the ARM. - // We get one report each cycle, and each report is 16 bits, so the - // ssp_clk should be the adc_clk divided by 64/16 = 4. - - if(corr_i_cnt[1:0] == 2'b10) - ssp_clk <= 1'b0; - - if(corr_i_cnt[1:0] == 2'b00) - begin - ssp_clk <= 1'b1; - // Don't shift if we just loaded new data, obviously. - if(corr_i_cnt != 6'd0) - begin - corr_i_out[7:0] <= {corr_i_out[6:0], corr_q_out[7]}; - corr_q_out[7:1] <= corr_q_out[6:0]; - end - end - - // set ssp_frame signal for corr_i_cnt = 0..3 and corr_i_cnt = 32..35 - // (send two frames with 8 Bits each) - if(corr_i_cnt[5:2] == 4'b0000 || corr_i_cnt[5:2] == 4'b1000) - ssp_frame = 1'b1; - else - ssp_frame = 1'b0; - -end - -assign ssp_din = corr_i_out[7]; - -assign dbg = corr_i_cnt[3]; - -// Unused. -assign pwr_lo = 1'b0; -assign pwr_oe2 = 1'b0; - -endmodule