fix 'hf iclass sim':

[proxmark3-svn] / fpga / hi_simulate.v

diff --git a/fpga/hi_simulate.v b/fpga/hi_simulate.v
index de58a74ec73af60429a6055cb494cfcbf4824911..92ebcb51387c48be14eef162931115c68096b04b 100644 (file)
--- a/fpga/hi_simulate.v
+++ b/fpga/hi_simulate.v
@@ -47,46 +47,48 @@ end
 
 // Divide 13.56 MHz to produce various frequencies for SSP_CLK
 // and modulation.
-reg [7:0] ssp_clk_divider;
+reg [8:0] ssp_clk_divider;
 
-always @(posedge adc_clk)
+always @(negedge adc_clk)
     ssp_clk_divider <= (ssp_clk_divider + 1);
 
 reg ssp_clk;
 
 always @(negedge adc_clk)
 begin
-    if(mod_type == `FPGA_HF_SIMULATOR_MODULATE_424K_8BIT)
+    if (mod_type == `FPGA_HF_SIMULATOR_MODULATE_424K_8BIT)
       // Get bit every at 53KHz (every 8th carrier bit of 424kHz)
-      ssp_clk <= ssp_clk_divider[7];
-    else if(mod_type == `FPGA_HF_SIMULATOR_MODULATE_212K)
+      ssp_clk <= ~ssp_clk_divider[7];
+    else if (mod_type == `FPGA_HF_SIMULATOR_MODULATE_212K)
       // Get next bit at 212kHz
-      ssp_clk <= ssp_clk_divider[5];
+      ssp_clk <= ~ssp_clk_divider[5];
     else
       // Get next bit at 424Khz
-      ssp_clk <= ssp_clk_divider[4];
+      ssp_clk <= ~ssp_clk_divider[4];
 end
 
 
-// Divide SSP_CLK by 8 to produce the byte framing signal; the phase of
-// this is arbitrary, because it's just a bitstream.
-// One nasty issue, though: I can't make it work with both rx and tx at
-// once. The phase wrt ssp_clk must be changed. TODO to find out why
-// that is and make a better fix.
-reg [2:0] ssp_frame_divider_to_arm;
-always @(posedge ssp_clk)
-    ssp_frame_divider_to_arm <= (ssp_frame_divider_to_arm + 1);
-reg [2:0] ssp_frame_divider_from_arm;
-always @(negedge ssp_clk)
-    ssp_frame_divider_from_arm <= (ssp_frame_divider_from_arm + 1);
-
-
+// Produce the byte framing signal; the phase of this signal 
+// is arbitrary, because it's just a bit stream in this module.
 reg ssp_frame;
-always @(ssp_frame_divider_to_arm or ssp_frame_divider_from_arm or mod_type)
-    if(mod_type == `FPGA_HF_SIMULATOR_NO_MODULATION) // not modulating, so listening, to ARM
-        ssp_frame = (ssp_frame_divider_to_arm == 3'b000);
-    else
-        ssp_frame = (ssp_frame_divider_from_arm == 3'b000);
+always @(negedge adc_clk)
+begin
+       if (mod_type == `FPGA_HF_SIMULATOR_MODULATE_212K)
+       begin
+               if (ssp_clk_divider[8:5] == 4'd1)
+                       ssp_frame <= 1'b1;
+               if (ssp_clk_divider[8:5] == 4'd5)
+                       ssp_frame <= 1'b0;
+       end
+       else
+       begin
+               if (ssp_clk_divider[7:4] == 4'd1)
+                       ssp_frame <= 1'b1;
+               if (ssp_clk_divider[7:4] == 4'd5)
+                       ssp_frame <= 1'b0;
+       end
+end
+
 
 // Synchronize up the after-hysteresis signal, to produce DIN.
 reg ssp_din;
@@ -120,6 +122,6 @@ assign pwr_lo = 1'b0;
 assign pwr_oe2 = 1'b0;
 
 
-assign dbg = ssp_din;
+assign dbg = ssp_frame;
 
 endmodule