hf topaz reader implementation:

[proxmark3-svn] / fpga / lo_passthru.v

diff --git a/fpga/lo_passthru.v b/fpga/lo_passthru.v
index 5c59d11ca6de2c2ac36faf0d1fc4c78ca36e21d7..3507f660ed69498d3dc671dff71f8a14fd672eff 100644 (file)
--- a/fpga/lo_passthru.v
+++ b/fpga/lo_passthru.v
@@ -2,44 +2,17 @@
 // For reading TI tags, we need to place the FPGA in pass through mode
 // and pass everything through to the ARM
 //-----------------------------------------------------------------------------
 // For reading TI tags, we need to place the FPGA in pass through mode
 // and pass everything through to the ARM
 //-----------------------------------------------------------------------------

+// iZsh <izsh at fail0verflow.com>, June 2014

 
 module lo_passthru(
 
 module lo_passthru(

-    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, divisor
+       input pck_divclk,
+       output pwr_lo, output pwr_hi,
+       output pwr_oe1, output pwr_oe2, output pwr_oe3, output pwr_oe4,
+       output adc_clk,
+       output ssp_din, input ssp_dout,
+       input cross_lo,
+       output dbg

 );
 );

-    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 [7:0] divisor;
-
-reg [7:0] pck_divider;
-reg ant_lo;
-
-// this task runs on the rising egde of pck0 clock (24Mhz) and creates ant_lo
-// which is high for (divisor+1) pck0 cycles and low for the same duration
-// ant_lo is therefore a 50% duty cycle clock signal with a frequency of
-// 12Mhz/(divisor+1) which drives the antenna as well as the ADC clock adc_clk
-always @(posedge pck0)
-begin
-       if(pck_divider == divisor[7:0])
-               begin
-                       pck_divider <= 8'd0;
-                       ant_lo = !ant_lo;
-               end
-       else
-       begin
-               pck_divider <= pck_divider + 1;
-       end
-end

 
 // the antenna is modulated when ssp_dout = 1, when 0 the
 // antenna drivers stop modulating and go into listen mode
 
 // the antenna is modulated when ssp_dout = 1, when 0 the
 // antenna drivers stop modulating and go into listen mode


@@ -47,7 +20,7 @@ assign pwr_oe3 = 1'b0;
 assign pwr_oe1 = ssp_dout;
 assign pwr_oe2 = ssp_dout;
 assign pwr_oe4 = ssp_dout;
 assign pwr_oe1 = ssp_dout;
 assign pwr_oe2 = ssp_dout;
 assign pwr_oe4 = ssp_dout;

-assign pwr_lo = ant_lo && ssp_dout;
+assign pwr_lo = pck_divclk && ssp_dout;

 assign pwr_hi = 1'b0;
 assign adc_clk = 1'b0;
 assign ssp_din = cross_lo;
 assign pwr_hi = 1'b0;
 assign adc_clk = 1'b0;
 assign ssp_din = cross_lo;