input ssp_dout;
output ssp_frame, ssp_din, ssp_clk;
output dbg;
- input [2:0] mod_type;
+ input [3:0] mod_type;
+assign adc_clk = ck_1356meg;
// The comparator with hysteresis on the output from the peak detector.
reg after_hysteresis;
-assign adc_clk = ck_1356meg;
+reg [11:0] has_been_low_for;
always @(negedge adc_clk)
begin
- if(& adc_d[7:5]) after_hysteresis = 1'b1; // if (adc_d >= 224)
- else if(~(| adc_d[7:5])) after_hysteresis = 1'b0; // if (adc_d <= 31)
+ if (& adc_d[7:5]) after_hysteresis <= 1'b1; // if (adc_d >= 224)
+ else if (~(| adc_d[7:5])) after_hysteresis <= 1'b0; // if (adc_d <= 31)
+
+ if (adc_d >= 224)
+ begin
+ has_been_low_for <= 12'd0;
+ end
+ else
+ begin
+ if (has_been_low_for == 12'd4095)
+ begin
+ has_been_low_for <= 12'd0;
+ after_hysteresis <= 1'b1;
+ end
+ else
+ begin
+ has_been_low_for <= has_been_low_for + 1;
+ end
+ end
end
// modulation than a real tag would.
assign pwr_hi = 1'b0; // HF antenna connected to GND
assign pwr_oe3 = 1'b0; // 10k Load
-assign pwr_oe1 = modulating_carrier; // 33 Ohms Load
+assign pwr_oe1 = 1'b0; // 33 Ohms Load
assign pwr_oe4 = modulating_carrier; // 33 Ohms Load
// This is all LF and doesn't matter