X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/467340996e7af6563070df2c96c374e6a97b1456..138927dd7b9be11990ac7073cdd1906b78683a76:/fpga/hi_read_rx_xcorr.v diff --git a/fpga/hi_read_rx_xcorr.v b/fpga/hi_read_rx_xcorr.v index f816199e..80e36327 100644 --- a/fpga/hi_read_rx_xcorr.v +++ b/fpga/hi_read_rx_xcorr.v @@ -28,11 +28,18 @@ assign pwr_oe1 = 1'b0; assign pwr_oe3 = 1'b0; assign pwr_oe4 = 1'b0; -wire adc_clk = ck_1356megb; - -reg fc_div_2; +// Clock divider +reg [0:0] fc_divider; always @(negedge ck_1356megb) - fc_div_2 <= fc_div_2 + 1; + 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, @@ -77,7 +84,6 @@ reg ssp_frame; always @(negedge adc_clk) begin - if (xcorr_is_848 | fc_div_2) corr_i_cnt <= corr_i_cnt + 1; end @@ -88,7 +94,7 @@ 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 == 7'd0) + if(corr_i_cnt == 6'd0) begin if(snoop) begin @@ -123,7 +129,7 @@ begin // 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'd31) + 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. @@ -137,7 +143,7 @@ begin begin ssp_clk <= 1'b1; // Don't shift if we just loaded new data, obviously. - if(corr_i_cnt != 7'd0) + 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];