Squashed B200 FPGA Source. Code from Josh Blum, Ian Buckley, and Matt Ettus.

1 files changed, 92 insertions, 0 deletions

diff --git a/fpga/usrp3/lib/vita/iq_to_float.v b/fpga/usrp3/lib/vita/iq_to_float.v
new file mode 100644
index 000000000..957b350db
--- /dev/null
+++ b/fpga/usrp3/lib/vita/iq_to_float.v
@@ -0,0 +1,92 @@
+module iq_to_float
+  
+  #(parameter BITS_IN =16,
+    parameter BITS_OUT = 32
+    )
+
+   (
+    input [15:0] in,
+    output [31:0] out
+
+    );
+
+   //imaginary
+   
+
+   //2s complement
+   wire [15:0] unsigned_mag;
+   wire [15:0] complement;
+ 
+   //leading bit registers
+   wire [15:0] lead;
+   wire [15:0] reversed_mag;
+   
+   //16-4 encoder
+   wire [3:0] binary_out;
+
+   wire [22:0] fraction;
+   wire [7:0] exponent;
+
+   wire [15:0] binary_in;
+   
+   binary_encoder #(.SIZE(16))
+   encoding
+     (.in(binary_in),.out(binary_out));
+   
+   
+
+   
+  
+   
+   // Detect sign, if negative detected perform 2's complement
+   
+   assign unsigned_mag = (in[15] == 1)?((~in[15:0])+1'b1):in[15:0];
+
+   //detect leading one 
+   
+   assign complement = ((~reversed_mag[BITS_IN-1:0])+1'b1);
+   
+   assign lead = complement & reversed_mag;
+
+   
+   
+   
+   
+   //calculate fraction and exponent using shift value generated
+
+  wire [15:0] pre_frac = unsigned_mag << ((15 - binary_out));
+  assign fraction = {pre_frac[14:0],8'h0};
+  assign exponent = (in == 16'b0)?(8'b0):(binary_out +'d127);
+
+
+      
+   
+   //construct the output
+   assign out = {in[15], exponent, fraction};
+
+   //reverse the signed input
+
+   genvar r;
+   
+   generate
+      for (r = 0; r < 16; r = r+1) begin:bit_reverse
+	assign reversed_mag[r] = unsigned_mag[BITS_IN-r-1];
+      end
+   endgenerate
+
+   //reversed the output of the detect the leading bit procedure
+
+   genvar i;
+    generate 
+	for (i= 0; i < 16; i = i+1) begin: i_rev
+			assign binary_in[i] = lead[BITS_IN-i-1];
+	end
+	endgenerate 
+	
+   
+   
+
+
+endmodule
+
+