Add raw HF signal plotting (#786)

[proxmark3-svn] / fpga / hi_get_trace.v

diff --git a/fpga/hi_get_trace.v b/fpga/hi_get_trace.v
new file mode 100644 (file)
index 0000000..7acecf8
--- /dev/null
+++ b/fpga/hi_get_trace.v
@@ -0,0 +1,160 @@
+//-----------------------------------------------------------------------------
+//
+// piwi, Feb 2019
+//-----------------------------------------------------------------------------
+
+module hi_get_trace(
+       ck_1356megb,
+       adc_d, trace_enable, major_mode,
+       ssp_frame, ssp_din, ssp_clk
+);
+    input ck_1356megb;
+    input [7:0] adc_d;
+       input trace_enable;
+       input [2:0] major_mode;
+    output ssp_frame, ssp_din, ssp_clk;
+
+// constants for some major_modes:
+`define OFF        3'b111
+`define GET_TRACE  3'b101
+
+
+// clock divider
+reg [6:0] clock_cnt;
+always @(negedge ck_1356megb)
+begin
+       clock_cnt <= clock_cnt + 1;
+end
+
+// sample at 13,56MHz / 8. The highest signal frequency (subcarrier) is 848,5kHz, i.e. in this case we oversample by a factor of 2
+reg [2:0] sample_clock;
+always @(negedge ck_1356megb)
+begin
+       if (sample_clock == 3'd3)
+               sample_clock <= 3'd0;
+       else
+               sample_clock <= sample_clock + 1;
+end
+
+
+reg [11:0] addr;
+reg [11:0] start_addr;
+reg [2:0] previous_major_mode;
+reg write_enable1;
+reg write_enable2;
+always @(negedge ck_1356megb)
+begin
+       previous_major_mode <= major_mode;
+       if (major_mode == `GET_TRACE)
+       begin
+               write_enable1 <= 1'b0;
+               write_enable2 <= 1'b0;
+               if (previous_major_mode != `GET_TRACE) // just switched into GET_TRACE mode
+                       addr <= start_addr;
+               if (clock_cnt == 7'd0)
+               begin
+                       if (addr == 12'd3071)
+                               addr <= 12'd0;
+                       else
+                               addr <= addr + 1;
+               end
+       end
+       else if (major_mode != `OFF)
+       begin
+               if (trace_enable)
+               begin
+                       if (addr[11] == 1'b0)
+                       begin
+                               write_enable1 <= 1'b1;
+                               write_enable2 <= 1'b0;
+                       end
+                       else
+                       begin
+                               write_enable1 <= 1'b0;
+                               write_enable2 <= 1'b1;
+                       end
+                       if (sample_clock == 3'b000)
+                       begin
+                               if (addr == 12'd3071)
+                               begin
+                                       addr <= 12'd0;
+                                       write_enable1 <= 1'b1;
+                                       write_enable2 <= 1'b0;
+                               end
+                               else
+                                       addr <= addr + 1;
+                       end
+               end
+               else
+               begin
+                       write_enable1 <= 1'b0;
+                       write_enable2 <= 1'b0;
+                       start_addr <= addr;
+               end
+       end
+       else // major_mode == `OFF
+       begin
+               write_enable1 <= 1'b0;
+               write_enable2 <= 1'b0;
+               if (previous_major_mode != `OFF && previous_major_mode != `GET_TRACE) // just switched off
+                       start_addr <= addr;
+       end
+end
+
+
+// (2+1)k RAM
+reg [7:0] D_out1, D_out2;
+reg [7:0] ram1 [2047:0];
+reg [7:0] ram2 [1023:0];
+
+always @(negedge ck_1356megb)
+begin
+       if (write_enable1)
+       begin
+               ram1[addr[10:0]] <= adc_d;
+               D_out1 <= adc_d;
+       end
+       else
+               D_out1 <= ram1[addr[10:0]];
+       if (write_enable2)
+       begin
+               ram2[addr[9:0]] <= adc_d;
+               D_out2 <= adc_d;
+       end
+       else
+               D_out2 <= ram2[addr[9:0]];
+end
+
+
+// SSC communication to ARM
+reg ssp_clk;
+reg ssp_frame;
+reg [7:0] shift_out;
+
+always @(negedge ck_1356megb)
+begin
+    if(clock_cnt[3:0] == 4'd0)        // update shift register every 16 clock cycles
+       begin
+               if(clock_cnt[6:4] == 3'd0)    // either load new value
+               begin
+                       if (addr[11] == 1'b0)
+                               shift_out <= D_out1;
+                       else
+                               shift_out <= D_out2;
+               end
+               else                          // or shift left
+            shift_out[7:1] <= shift_out[6:0];
+       end
+
+       ssp_clk <= ~clock_cnt[3];       // ssp_clk frequency = 13,56MHz / 16 = 847,5 kHz
+
+       if(clock_cnt[6:4] == 3'b000)    // set ssp_frame for 0...31
+               ssp_frame <= 1'b1;
+       else
+               ssp_frame <= 1'b0;
+
+end
+
+assign ssp_din = shift_out[7];
+
+endmodule