Moved usrp2 fpga files into usrp2 subdir.

64 files changed, 5131 insertions, 0 deletions

diff --git a/usrp2/sdr_lib/.gitignore b/usrp2/sdr_lib/.gitignore
new file mode 100644
index 000000000..3c782d589
--- /dev/null
+++ b/usrp2/sdr_lib/.gitignore
@@ -0,0 +1,3 @@
+/a.out
+/db
+/*.vcd
diff --git a/usrp2/sdr_lib/HB.sav b/usrp2/sdr_lib/HB.sav
new file mode 100644
index 000000000..c5087e8a6
--- /dev/null
+++ b/usrp2/sdr_lib/HB.sav
@@ -0,0 +1,56 @@
+[size] 1400 967
+[pos] -1 -1
+*-46.395245 2565000000000000 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
+[treeopen] hb_dec_tb.
+@420
+hb_dec_tb.data_in[17:0]
+@28
+hb_dec_tb.strobe_in
+hb_dec_tb.strobe_out
+hb_dec_tb.uut.write_even
+@22
+hb_dec_tb.uut.addr_even[3:0]
+@420
+hb_dec_tb.uut.data_even[17:0]
+hb_dec_tb.uut.data_odd_a[17:0]
+hb_dec_tb.uut.data_odd_b[17:0]
+hb_dec_tb.uut.data_odd_c[17:0]
+hb_dec_tb.uut.data_odd_d[17:0]
+@28
+hb_dec_tb.uut.write_odd
+@420
+hb_dec_tb.uut.prod1[35:0]
+hb_dec_tb.uut.prod2[35:0]
+@24
+hb_dec_tb.uut.phase[2:0]
+@28
+hb_dec_tb.uut.stb_in
+hb_dec_tb.uut.stb_out
+@420
+hb_dec_tb.uut.sum2[17:0]
+hb_dec_tb.uut.stb_out_pre[15:0]
+@28
+hb_dec_tb.uut.do_acc
+hb_dec_tb.uut.clear
+@420
+hb_dec_tb.uut.sum1[17:0]
+hb_dec_tb.uut.coeff1[17:0]
+hb_dec_tb.uut.prod1[35:0]
+hb_dec_tb.uut.prod2[35:0]
+hb_dec_tb.uut.final_sum[17:0]
+hb_dec_tb.uut.coeff2[17:0]
+hb_dec_tb.uut.sum_of_prod[21:0]
+hb_dec_tb.data_out[17:0]
+@28
+hb_dec_tb.uut.do_acc
+hb_dec_tb.uut.clear
+@24
+hb_dec_tb.uut.addr_odd_a[3:0]
+hb_dec_tb.uut.addr_odd_b[3:0]
+hb_dec_tb.uut.addr_odd_c[3:0]
+hb_dec_tb.uut.addr_odd_d[3:0]
+@28
+hb_dec_tb.uut.write_odd
+hb_dec_tb.uut.write_even
+@22
+hb_dec_tb.uut.data_even[17:0]
diff --git a/usrp2/sdr_lib/SMALL_HB.sav b/usrp2/sdr_lib/SMALL_HB.sav
new file mode 100644
index 000000000..96ba00636
--- /dev/null
+++ b/usrp2/sdr_lib/SMALL_HB.sav
@@ -0,0 +1,40 @@
+[size] 1400 967
+[pos] -1 -1
+*-11.608687 1834 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
+[treeopen] small_hb_dec_tb.
+[treeopen] small_hb_dec_tb.uut.
+@28
+small_hb_dec_tb.uut.clk
+small_hb_dec_tb.uut.phase
+@10421
+small_hb_dec_tb.uut.data_in[17:0]
+@420
+small_hb_dec_tb.uut.d1[17:0]
+small_hb_dec_tb.uut.d2[17:0]
+small_hb_dec_tb.uut.d3[17:0]
+small_hb_dec_tb.uut.d4[17:0]
+small_hb_dec_tb.uut.d5[17:0]
+small_hb_dec_tb.uut.d6[17:0]
+small_hb_dec_tb.uut.coeff[17:0]
+small_hb_dec_tb.uut.sum[17:0]
+small_hb_dec_tb.uut.prod[35:0]
+small_hb_dec_tb.uut.accum_rnd[17:0]
+@28
+small_hb_dec_tb.uut.stb_in
+@420
+small_hb_dec_tb.uut.final_sum[17:0]
+@28
+small_hb_dec_tb.uut.go
+small_hb_dec_tb.uut.go_d1
+small_hb_dec_tb.uut.go_d2
+small_hb_dec_tb.uut.go_d3
+small_hb_dec_tb.uut.go_d4
+small_hb_dec_tb.uut.stb_out
+@420
+small_hb_dec_tb.uut.data_out[17:0]
+small_hb_dec_tb.uut.prod[35:0]
+small_hb_dec_tb.uut.accum_rnd[17:0]
+small_hb_dec_tb.uut.final_sum[17:0]
+@10421
+small_hb_dec_tb.uut.round_acc.out[17:0]
+small_hb_dec_tb.uut.data_out[17:0]
diff --git a/usrp2/sdr_lib/acc.v b/usrp2/sdr_lib/acc.v
new file mode 100644
index 000000000..a2da9c86d
--- /dev/null
+++ b/usrp2/sdr_lib/acc.v
@@ -0,0 +1,28 @@
+
+module acc
+  #(parameter IWIDTH=16, OWIDTH=30)
+    (input clk,
+     input clear,
+     input acc,
+     input [IWIDTH-1:0] in,
+     output reg [OWIDTH-1:0] out);
+
+   wire [OWIDTH-1:0] in_signext;
+   sign_extend #(.bits_in(IWIDTH),.bits_out(OWIDTH)) 
+     acc_signext (.in(in),.out(in_signext));
+   
+   //  CLEAR & ~ACC  -->  clears the accumulator
+   //  CLEAR & ACC -->    loads the accumulator
+   //  ~CLEAR & ACC -->   accumulates
+   //  ~CLEAR & ~ACC -->  hold
+   
+   wire [OWIDTH-1:0] addend1 = clear ? 0 : out;
+   wire [OWIDTH-1:0] addend2 = ~acc ? 0 : in_signext;
+   wire [OWIDTH-1:0] sum_int = addend1 + addend2;
+
+   always @(posedge clk)
+     out <= sum_int;
+   
+endmodule // acc
+
+
diff --git a/usrp2/sdr_lib/add2.v b/usrp2/sdr_lib/add2.v
new file mode 100644
index 000000000..13fff803e
--- /dev/null
+++ b/usrp2/sdr_lib/add2.v
@@ -0,0 +1,11 @@
+
+module add2
+  #(parameter WIDTH=16)
+    (input [WIDTH-1:0] in1,
+     input [WIDTH-1:0] in2,
+     output [WIDTH-1:0] sum);
+
+   wire [WIDTH:0] 	sum_int = {in1[WIDTH-1],in1} + {in2[WIDTH-1],in2};
+   assign 		sum = sum_int[WIDTH:1];  // Note -- will have some bias
+   
+endmodule // add2
diff --git a/usrp2/sdr_lib/add2_and_round.v b/usrp2/sdr_lib/add2_and_round.v
new file mode 100644
index 000000000..146af28da
--- /dev/null
+++ b/usrp2/sdr_lib/add2_and_round.v
@@ -0,0 +1,11 @@
+
+module add2_and_round
+  #(parameter WIDTH=16)
+    (input [WIDTH-1:0] in1,
+     input [WIDTH-1:0] in2,
+     output [WIDTH-1:0] sum);
+
+   wire [WIDTH:0] 	sum_int = {in1[WIDTH-1],in1} + {in2[WIDTH-1],in2};
+   assign 		sum = sum_int[WIDTH:1] + (sum_int[WIDTH] & sum_int[0]);
+   
+endmodule // add2_and_round
diff --git a/usrp2/sdr_lib/add2_and_round_reg.v b/usrp2/sdr_lib/add2_and_round_reg.v
new file mode 100644
index 000000000..e7fcbf1a1
--- /dev/null
+++ b/usrp2/sdr_lib/add2_and_round_reg.v
@@ -0,0 +1,16 @@
+
+module add2_and_round_reg
+  #(parameter WIDTH=16)
+    (input clk,
+     input [WIDTH-1:0] in1,
+     input [WIDTH-1:0] in2,
+     output reg [WIDTH-1:0] sum);
+
+   wire [WIDTH-1:0] sum_int;
+   
+   add2_and_round #(.WIDTH(WIDTH)) add2_n_rnd (.in1(in1),.in2(in2),.sum(sum_int));
+
+   always @(posedge clk)
+     sum <= sum_int;
+   
+endmodule // add2_and_round_reg
diff --git a/usrp2/sdr_lib/add2_reg.v b/usrp2/sdr_lib/add2_reg.v
new file mode 100644
index 000000000..456cf315b
--- /dev/null
+++ b/usrp2/sdr_lib/add2_reg.v
@@ -0,0 +1,17 @@
+
+module add2_reg
+  #(parameter WIDTH=16)
+    (input clk,
+     input [WIDTH-1:0] in1,
+     input [WIDTH-1:0] in2,
+     output reg [WIDTH-1:0] sum);
+
+   wire [WIDTH-1:0] sum_int;
+   
+   add2 #(.WIDTH(WIDTH)) add2 (.in1(in1),.in2(in2),.sum(sum_int));
+
+   always @(posedge clk)
+     sum <= sum_int;
+   
+endmodule // add2_reg
+
diff --git a/usrp2/sdr_lib/cic_dec_shifter.v b/usrp2/sdr_lib/cic_dec_shifter.v
new file mode 100644
index 000000000..aa5ac895b
--- /dev/null
+++ b/usrp2/sdr_lib/cic_dec_shifter.v
@@ -0,0 +1,106 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+
+// NOTE   This only works for N=4, max decim rate of 128
+// NOTE   signal "rate" is EQUAL TO the actual rate, no more -1 BS
+
+module cic_dec_shifter(rate,signal_in,signal_out);
+   parameter bw = 16;
+   parameter maxbitgain = 28;
+
+   input [7:0] rate;
+   input       wire [bw+maxbitgain-1:0] signal_in;
+   output      reg [bw-1:0] signal_out;
+
+   function [4:0] bitgain;
+      input [7:0] rate;
+      case(rate)
+	// Exact Cases -- N*log2(rate)
+	8'd1 : bitgain = 0;
+	8'd2 : bitgain = 4;
+	8'd4 : bitgain = 8;
+	8'd8 : bitgain = 12;
+	8'd16 : bitgain = 16;
+	8'd32 : bitgain = 20;
+	8'd64 : bitgain = 24;
+	8'd128 : bitgain = 28;
+	
+	// Nearest without overflow -- ceil(N*log2(rate))
+	8'd3 : bitgain = 7;
+	8'd5 : bitgain = 10;
+	8'd6 : bitgain = 11;
+	8'd7 : bitgain = 12;
+	8'd9 : bitgain = 13;
+	8'd10,8'd11 : bitgain = 14;
+	8'd12,8'd13 : bitgain = 15;
+	8'd14,8'd15 : bitgain = 16;
+	8'd17,8'd18,8'd19 : bitgain = 17;
+	8'd20,8'd21,8'd22 : bitgain = 18;
+	8'd23,8'd24,8'd25,8'd26 : bitgain = 19;
+	8'd27,8'd28,8'd29,8'd30,8'd31 : bitgain = 20;
+	8'd33,8'd34,8'd35,8'd36,8'd37,8'd38 : bitgain = 21;
+	8'd39,8'd40,8'd41,8'd42,8'd43,8'd44,8'd45 : bitgain = 22;
+	8'd46,8'd47,8'd48,8'd49,8'd50,8'd51,8'd52,8'd53 : bitgain = 23;
+	8'd54,8'd55,8'd56,8'd57,8'd58,8'd59,8'd60,8'd61,8'd62,8'd63 : bitgain = 24;
+	8'd65,8'd66,8'd67,8'd68,8'd69,8'd70,8'd71,8'd72,8'd73,8'd74,8'd75,8'd76 : bitgain = 25;
+	8'd77,8'd78,8'd79,8'd80,8'd81,8'd82,8'd83,8'd84,8'd85,8'd86,8'd87,8'd88,8'd89,8'd90 : bitgain = 26;
+	8'd91,8'd92,8'd93,8'd94,8'd95,8'd96,8'd97,8'd98,8'd99,8'd100,8'd101,8'd102,8'd103,8'd104,8'd105,8'd106,8'd107 : bitgain = 27;
+	default : bitgain = 28;
+      endcase // case(rate)
+   endfunction // bitgain
+   
+   wire [4:0] 	  shift = bitgain(rate);
+   
+   // We should be able to do this, but can't ....
+   // assign 	  signal_out = signal_in[shift+bw-1:shift];
+   
+   always @*
+     case(shift)
+       5'd0  : signal_out = signal_in[0+bw-1:0];
+       5'd4  : signal_out = signal_in[4+bw-1:4];
+       5'd7  : signal_out = signal_in[7+bw-1:7];
+       5'd8  : signal_out = signal_in[8+bw-1:8];
+       5'd10 : signal_out = signal_in[10+bw-1:10];
+       5'd11 : signal_out = signal_in[11+bw-1:11];
+       5'd12 : signal_out = signal_in[12+bw-1:12];
+       5'd13 : signal_out = signal_in[13+bw-1:13];
+       5'd14 : signal_out = signal_in[14+bw-1:14];
+       5'd15 : signal_out = signal_in[15+bw-1:15];
+       5'd16 : signal_out = signal_in[16+bw-1:16];
+       5'd17 : signal_out = signal_in[17+bw-1:17];
+       5'd18 : signal_out = signal_in[18+bw-1:18];
+       5'd19 : signal_out = signal_in[19+bw-1:19];
+       5'd20 : signal_out = signal_in[20+bw-1:20];
+       5'd21 : signal_out = signal_in[21+bw-1:21];
+       5'd22 : signal_out = signal_in[22+bw-1:22];
+       5'd23 : signal_out = signal_in[23+bw-1:23];
+       5'd24 : signal_out = signal_in[24+bw-1:24];
+       5'd25 : signal_out = signal_in[25+bw-1:25];
+       5'd26 : signal_out = signal_in[26+bw-1:26];
+       5'd27 : signal_out = signal_in[27+bw-1:27];
+       5'd28 : signal_out = signal_in[28+bw-1:28];
+       
+       default : signal_out = signal_in[28+bw-1:28];
+     endcase // case(shift)
+
+endmodule // cic_dec_shifter
+
diff --git a/usrp2/sdr_lib/cic_decim.v b/usrp2/sdr_lib/cic_decim.v
new file mode 100755
index 000000000..9a03081b0
--- /dev/null
+++ b/usrp2/sdr_lib/cic_decim.v
@@ -0,0 +1,88 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+
+module cic_decim
+  #(parameter bw = 16, parameter N = 4, parameter log2_of_max_rate = 7)
+    (input clock,
+     input reset,
+     input enable,
+     input [7:0] rate,
+     input strobe_in,
+     input strobe_out,
+     input [bw-1:0] signal_in,
+     output reg [bw-1:0] signal_out);
+
+   localparam 	     maxbitgain = N * log2_of_max_rate;
+   
+   wire [bw+maxbitgain-1:0] signal_in_ext;
+   reg [bw+maxbitgain-1:0]  integrator [0:N-1];
+   reg [bw+maxbitgain-1:0]  differentiator [0:N-1];
+   reg [bw+maxbitgain-1:0]  pipeline [0:N-1];
+   reg [bw+maxbitgain-1:0]  sampler;
+   
+   integer 		    i;
+   
+   sign_extend #(bw,bw+maxbitgain) 
+     ext_input (.in(signal_in),.out(signal_in_ext));
+   
+   always @(posedge clock)
+     if(reset)
+       for(i=0;i<N;i=i+1)
+	 integrator[i] <= 0;
+     else if (enable && strobe_in)
+       begin
+	  integrator[0] <= integrator[0] + signal_in_ext;
+	  for(i=1;i<N;i=i+1)
+	    integrator[i] <= integrator[i] + integrator[i-1];
+       end	
+   
+   always @(posedge clock)
+     if(reset)
+       begin
+	  sampler <= 0;
+	  for(i=0;i<N;i=i+1)
+	    begin
+	       pipeline[i] <= 0;
+	       differentiator[i] <= 0;
+	    end
+       end
+     else if (enable && strobe_out)
+       begin
+	  sampler <= integrator[N-1];
+	  differentiator[0] <= sampler;
+	  pipeline[0] <= sampler - differentiator[0];
+	  for(i=1;i<N;i=i+1)
+	    begin
+	       differentiator[i] <= pipeline[i-1];
+	       pipeline[i] <= pipeline[i-1] - differentiator[i];
+	    end
+       end // if (enable && strobe_out)
+   
+   wire [bw-1:0] signal_out_unreg;
+   
+   cic_dec_shifter #(bw)
+     cic_dec_shifter(rate,pipeline[N-1],signal_out_unreg);
+
+   always @(posedge clock)
+     signal_out <= signal_out_unreg;
+   
+endmodule // cic_decim
diff --git a/usrp2/sdr_lib/cic_int_shifter.v b/usrp2/sdr_lib/cic_int_shifter.v
new file mode 100644
index 000000000..18587fa8b
--- /dev/null
+++ b/usrp2/sdr_lib/cic_int_shifter.v
@@ -0,0 +1,100 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+
+// NOTE   This only works for N=4, max interp rate of 128
+// NOTE   signal "rate" is EQUAL TO the actual rate (no more -1 BS)
+
+module cic_int_shifter(rate,signal_in,signal_out);
+   parameter bw = 16;
+   parameter maxbitgain = 21;
+   
+   input [7:0] rate;
+   input       wire [bw+maxbitgain-1:0] signal_in;
+   output      reg [bw-1:0] signal_out;
+
+   function [4:0] bitgain;
+      input [7:0] rate;
+      case(rate)
+	// Exact Cases
+	8'd1 : bitgain = 0;
+	8'd2 : bitgain = 3;
+	8'd4 : bitgain = 6;
+	8'd8 : bitgain = 9;
+	8'd16 : bitgain = 12;
+	8'd32 : bitgain = 15;
+	8'd64 : bitgain = 18;
+	8'd128 : bitgain = 21;
+	
+	// Nearest without overflow	
+	8'd3 : bitgain = 5;
+	8'd5 : bitgain = 7;
+	8'd6 : bitgain = 8;
+	8'd7 : bitgain = 9;
+	8'd9,8'd10 : bitgain = 10;
+	8'd11,8'd12 : bitgain = 11;
+	8'd13,8'd14,8'd15 : bitgain = 12;
+	8'd17,8'd18,8'd19,8'd20 : bitgain = 13;
+	8'd21,8'd22,8'd23,8'd24,8'd25 : bitgain = 14;
+	8'd26,8'd27,8'd28,8'd29,8'd30,8'd31 : bitgain = 15;
+	8'd33,8'd34,8'd35,8'd36,8'd37,8'd38,8'd39,8'd40 : bitgain = 16;
+	8'd41,8'd42,8'd43,8'd44,8'd45,8'd46,8'd47,8'd48,8'd49,8'd50 : bitgain = 17;
+	8'd51,8'd52,8'd53,8'd54,8'd55,8'd56,8'd57,8'd58,8'd59,8'd60,8'd61,8'd62,8'd63 : bitgain = 18;
+	8'd65,8'd66,8'd67,8'd68,8'd69,8'd70,8'd71,8'd72,8'd73,8'd74,8'd75,8'd76,8'd77,8'd78,8'd79,8'd80 : bitgain = 19;
+	8'd81,8'd82,8'd83,8'd84,8'd85,8'd86,8'd87,8'd88,8'd89,8'd90,8'd91,8'd92,8'd93,8'd94,8'd95,8'd96,8'd97,8'd98,8'd99,8'd100,8'd101 : bitgain = 20;
+	
+	default : bitgain = 21;
+      endcase // case(rate)
+   endfunction // bitgain
+   
+   wire [4:0] 	  shift = bitgain(rate);
+   
+   // We should be able to do this, but can't ....
+   // assign 	  signal_out = signal_in[shift+bw-1:shift];
+   
+   always @*
+     case(shift)
+       5'd0  : signal_out = signal_in[0+bw-1:0];
+       5'd3  : signal_out = signal_in[3+bw-1:3];
+       5'd6  : signal_out = signal_in[6+bw-1:6];
+       5'd9  : signal_out = signal_in[9+bw-1:9];
+       5'd12 : signal_out = signal_in[12+bw-1:12];
+       5'd15 : signal_out = signal_in[15+bw-1:15];
+       5'd18 : signal_out = signal_in[18+bw-1:18];
+       5'd21 : signal_out = signal_in[21+bw-1:21];
+       
+       5'd5  : signal_out = signal_in[5+bw-1:5];
+       5'd7  : signal_out = signal_in[7+bw-1:7];
+       5'd8  : signal_out = signal_in[8+bw-1:8];
+       5'd10 : signal_out = signal_in[10+bw-1:10];
+       5'd11 : signal_out = signal_in[11+bw-1:11];
+       5'd13 : signal_out = signal_in[13+bw-1:13];
+       5'd14 : signal_out = signal_in[14+bw-1:14];
+       5'd16 : signal_out = signal_in[16+bw-1:16];
+       5'd17 : signal_out = signal_in[17+bw-1:17];
+       5'd19 : signal_out = signal_in[19+bw-1:19];
+       5'd20 : signal_out = signal_in[20+bw-1:20];
+       
+       default : signal_out = signal_in[21+bw-1:21];
+     endcase // case(shift)
+
+endmodule // cic_int_shifter
+
diff --git a/usrp2/sdr_lib/cic_interp.v b/usrp2/sdr_lib/cic_interp.v
new file mode 100755
index 000000000..9b6928aa1
--- /dev/null
+++ b/usrp2/sdr_lib/cic_interp.v
@@ -0,0 +1,87 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+
+module cic_interp
+  #(parameter bw = 16, parameter N = 4, parameter log2_of_max_rate = 7)
+    (input clock,
+     input reset,
+     input enable,
+     input [7:0] rate,
+     input strobe_in,
+     input strobe_out,
+     input [bw-1:0] signal_in,
+     output reg [bw-1:0] signal_out);
+   
+   integer 	     i;
+   localparam 	     maxbitgain = (N-1)*log2_of_max_rate;
+
+   wire [bw+maxbitgain-1:0] signal_in_ext;
+   reg [bw+maxbitgain-1:0]  integrator [0:N-1];
+   reg [bw+maxbitgain-1:0]  differentiator [0:N-1];
+   reg [bw+maxbitgain-1:0]  pipeline [0:N-1];
+   
+   sign_extend #(bw,bw+maxbitgain) 
+     ext_input (.in(signal_in),.out(signal_in_ext));
+   
+   //FIXME Note that this section has pipe and diff reversed
+   // It still works, but is confusing
+   always @(posedge clock)
+     if(reset | ~enable)
+       for(i=0;i<N;i=i+1)
+	 integrator[i] <= 0;
+     else if (enable & strobe_out)
+       begin
+	  if(strobe_in)
+	    integrator[0] <= integrator[0] + pipeline[N-1];
+	  for(i=1;i<N;i=i+1)
+	    integrator[i] <= integrator[i] + integrator[i-1];
+       end
+   
+   always @(posedge clock)
+     if(reset | ~enable)
+       begin
+	  for(i=0;i<N;i=i+1)
+	    begin
+	       differentiator[i] <= 0;
+	       pipeline[i] <= 0;
+ 	    end
+       end
+     else if (enable && strobe_in)
+       begin
+	  differentiator[0] <= signal_in_ext;
+	  pipeline[0] <= signal_in_ext - differentiator[0];
+	  for(i=1;i<N;i=i+1)
+	    begin
+	       differentiator[i] <= pipeline[i-1];
+	       pipeline[i] <= pipeline[i-1] - differentiator[i];
+	    end
+       end
+
+   wire [bw-1:0] signal_out_unreg;
+   cic_int_shifter #(bw)
+     cic_int_shifter(rate,integrator[N-1],signal_out_unreg);
+   
+   always @(posedge clock)
+     signal_out <= signal_out_unreg;
+   
+endmodule // cic_interp
+
diff --git a/usrp2/sdr_lib/cic_strober.v b/usrp2/sdr_lib/cic_strober.v
new file mode 100644
index 000000000..40d76bdd9
--- /dev/null
+++ b/usrp2/sdr_lib/cic_strober.v
@@ -0,0 +1,45 @@
+//
+//  USRP2 - Universal Software Radio Peripheral Mk II
+//
+//  Copyright (C) 2008 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+module cic_strober
+  #(parameter WIDTH=8)
+    ( input clock,
+      input reset,
+      input enable,
+      input [WIDTH-1:0] rate, // Rate should EQUAL to your desired divide ratio, no more -1 BS
+      input strobe_fast,
+      output wire strobe_slow );
+   
+   reg [WIDTH-1:0] counter;
+   wire      now = (counter==1);
+   assign    strobe_slow = now && enable && strobe_fast;
+   
+   always @(posedge clock)
+     if(reset)
+       counter <= 0; 
+     else if (~enable)
+       counter <= rate;
+     else if(strobe_fast)
+       if(now)
+	 counter <= rate;
+       else 
+	 counter <= counter - 1;
+   
+endmodule // cic_strober
diff --git a/usrp2/sdr_lib/clip.v b/usrp2/sdr_lib/clip.v
new file mode 100644
index 000000000..3e6b3a2e2
--- /dev/null
+++ b/usrp2/sdr_lib/clip.v
@@ -0,0 +1,36 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2008 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+// Clipping "macro", keeps the bottom bits
+
+module clip
+  #(parameter bits_in=0,
+    parameter bits_out=0)
+    (input [bits_in-1:0] in,
+     output [bits_out-1:0] out);
+   
+   wire 		   overflow = |in[bits_in-1:bits_out-1] & ~(&in[bits_in-1:bits_out-1]);   
+   assign 		   out = overflow ? 
+			   (in[bits_in-1] ? {1'b1,{(bits_out-1){1'b0}}} : {1'b0,{(bits_out-1){1'b1}}}) :
+			   in[bits_out-1:0];
+   
+endmodule // clip
+
diff --git a/usrp2/sdr_lib/clip_and_round.v b/usrp2/sdr_lib/clip_and_round.v
new file mode 100644
index 000000000..4546283a3
--- /dev/null
+++ b/usrp2/sdr_lib/clip_and_round.v
@@ -0,0 +1,43 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2008 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+// Clipping "macro", keeps the bottom bits
+
+module clip_and_round
+  #(parameter bits_in=0,
+    parameter bits_out=0,
+    parameter clip_bits=0)
+    (input [bits_in-1:0] in,
+     output [bits_out-1:0] out);
+
+   wire [bits_out-1:0] 	   rounded;
+   
+   round #(.bits_in(bits_in-clip_bits),.bits_out(bits_out))
+     round (.in(in[bits_in-clip_bits-1:0]),.out(rounded));
+   
+   wire 		   overflow = |in[bits_in-1:bits_in-clip_bits-1] 
+			   & ~(&in[bits_in-1:bits_in-clip_bits-1]);
+   
+   assign 		   out = overflow ? 
+			   (in[bits_in-1] ? {1'b1,{(bits_out-1){1'b0}}} : {1'b0,{(bits_out-1){1'b1}}}) :
+			   rounded;
+   
+endmodule // clip_and_round
diff --git a/usrp2/sdr_lib/clip_and_round_reg.v b/usrp2/sdr_lib/clip_and_round_reg.v
new file mode 100644
index 000000000..66fb155fb
--- /dev/null
+++ b/usrp2/sdr_lib/clip_and_round_reg.v
@@ -0,0 +1,40 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2008 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+// Clipping "macro", keeps the bottom bits
+
+module clip_and_round_reg
+  #(parameter bits_in=0,
+    parameter bits_out=0,
+    parameter clip_bits=0)
+    (input clk,
+     input [bits_in-1:0] in,
+     output reg [bits_out-1:0] out);
+
+   wire [bits_out-1:0] 	   temp;
+
+   clip_and_round #(.bits_in(bits_in),.bits_out(bits_out),.clip_bits(clip_bits))
+     clip_and_round (.in(in),.out(temp));
+
+   always@(posedge clk)
+     out <= temp;
+   
+endmodule // clip_and_round_reg
diff --git a/usrp2/sdr_lib/clip_reg.v b/usrp2/sdr_lib/clip_reg.v
new file mode 100644
index 000000000..d5e98d982
--- /dev/null
+++ b/usrp2/sdr_lib/clip_reg.v
@@ -0,0 +1,38 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2008 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+// Clipping "macro", keeps the bottom bits
+
+module clip_reg
+  #(parameter bits_in=0,
+    parameter bits_out=0)
+    (input clk,
+     input [bits_in-1:0] in,
+     output reg [bits_out-1:0] out);
+   
+   wire [bits_out-1:0] temp;
+
+   clip #(.bits_in(bits_in),.bits_out(bits_out)) clip (.in(in),.out(temp));
+   always @(posedge clk)
+     out <= temp;
+   
+endmodule // clip_reg
+
diff --git a/usrp2/sdr_lib/cordic.v b/usrp2/sdr_lib/cordic.v
new file mode 100755
index 000000000..b73e7acf1
--- /dev/null
+++ b/usrp2/sdr_lib/cordic.v
@@ -0,0 +1,109 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003, 2007 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+module cordic(clock, reset, enable, xi, yi, zi, xo, yo, zo );
+   parameter bitwidth = 16;
+   parameter zwidth = 16;
+   
+   input clock;
+   input reset;
+   input enable;
+   input [bitwidth-1:0] xi, yi;
+   output [bitwidth-1:0] xo, yo;
+   input [zwidth-1:0] zi;
+   output [zwidth-1:0] zo;
+   
+   reg [bitwidth+1:0] 	 x0,y0;
+   reg [zwidth-2:0] 	 z0;
+   wire [bitwidth+1:0] 	 x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12;
+   wire [bitwidth+1:0] 	 y1,y2,y3,y4,y5,y6,y7,y8,y9,y10,y11,y12;
+   wire [zwidth-2:0] z1,z2,z3,z4,z5,z6,z7,z8,z9,z10,z11,z12;
+   
+   wire [bitwidth+1:0] xi_ext = {{2{xi[bitwidth-1]}},xi};
+   wire [bitwidth+1:0] yi_ext = {{2{yi[bitwidth-1]}},yi};
+
+   // Compute consts.  Would be easier if vlog had atan...
+   // see gen_cordic_consts.py
+   
+   localparam 	       c00 = 15'd8192;
+   localparam 	       c01 = 15'd4836;
+   localparam 	       c02 = 15'd2555;
+   localparam 	       c03 = 15'd1297;
+   localparam 	       c04 = 15'd651;
+   localparam 	       c05 = 15'd326;
+   localparam 	       c06 = 15'd163;
+   localparam 	       c07 = 15'd81;
+   localparam 	       c08 = 15'd41;
+   localparam 	       c09 = 15'd20;
+   localparam 	       c10 = 15'd10;
+   localparam 	       c11 = 15'd5;
+   localparam 	       c12 = 15'd3;
+   localparam 	       c13 = 15'd1;
+   localparam 	       c14 = 15'd1;
+   localparam 	       c15 = 15'd0;
+   localparam 	       c16 = 15'd0;
+   
+   always @(posedge clock)
+     if(reset)
+       begin
+	  x0   <= 0; y0   <= 0;  z0   <= 0;
+       end
+     else// if(enable)
+       begin
+	  z0 <= zi[zwidth-2:0];
+	  case (zi[zwidth-1:zwidth-2])
+	    2'b00, 2'b11 : 
+	      begin
+		 x0 <= xi_ext;
+		 y0 <= yi_ext;
+	      end
+	    2'b01, 2'b10 :
+	      begin
+		 x0 <= -xi_ext;
+		 y0 <= -yi_ext;
+	      end
+	  endcase // case(zi[zwidth-1:zwidth-2])
+       end // else: !if(reset)
+   
+   // FIXME need to handle variable number of stages
+   // FIXME should be able to narrow zwidth but quartus makes it bigger...
+   // This would be easier if arrays worked better in vlog...
+   cordic_stage #(bitwidth+2,zwidth-1,0) cordic_stage0 (clock,reset,enable,x0,y0,z0,c00,x1,y1,z1);
+   cordic_stage #(bitwidth+2,zwidth-1,1) cordic_stage1 (clock,reset,enable,x1,y1,z1,c01,x2,y2,z2);
+   cordic_stage #(bitwidth+2,zwidth-1,2) cordic_stage2 (clock,reset,enable,x2,y2,z2,c02,x3,y3,z3);
+   cordic_stage #(bitwidth+2,zwidth-1,3) cordic_stage3 (clock,reset,enable,x3,y3,z3,c03,x4,y4,z4);
+   cordic_stage #(bitwidth+2,zwidth-1,4) cordic_stage4 (clock,reset,enable,x4,y4,z4,c04,x5,y5,z5);
+   cordic_stage #(bitwidth+2,zwidth-1,5) cordic_stage5 (clock,reset,enable,x5,y5,z5,c05,x6,y6,z6);
+   cordic_stage #(bitwidth+2,zwidth-1,6) cordic_stage6 (clock,reset,enable,x6,y6,z6,c06,x7,y7,z7);
+   cordic_stage #(bitwidth+2,zwidth-1,7) cordic_stage7 (clock,reset,enable,x7,y7,z7,c07,x8,y8,z8);
+   cordic_stage #(bitwidth+2,zwidth-1,8) cordic_stage8 (clock,reset,enable,x8,y8,z8,c08,x9,y9,z9);
+   cordic_stage #(bitwidth+2,zwidth-1,9) cordic_stage9 (clock,reset,enable,x9,y9,z9,c09,x10,y10,z10);
+   cordic_stage #(bitwidth+2,zwidth-1,10) cordic_stage10 (clock,reset,enable,x10,y10,z10,c10,x11,y11,z11);
+   cordic_stage #(bitwidth+2,zwidth-1,11) cordic_stage11 (clock,reset,enable,x11,y11,z11,c11,x12,y12,z12);
+
+   assign xo = x12[bitwidth:1];  
+   assign yo = y12[bitwidth:1];
+   //assign xo = x12[bitwidth+1:2];  // CORDIC gain is ~1.6, plus gain from rotating vectors
+   //assign yo = y12[bitwidth+1:2];
+   assign zo = z12;		  
+
+endmodule // cordic
+
diff --git a/usrp2/sdr_lib/cordic_stage.v b/usrp2/sdr_lib/cordic_stage.v
new file mode 100755
index 000000000..641ff9108
--- /dev/null
+++ b/usrp2/sdr_lib/cordic_stage.v
@@ -0,0 +1,60 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+module cordic_stage( clock, reset, enable, xi,yi,zi,constant,xo,yo,zo);
+   parameter bitwidth = 16;
+   parameter zwidth = 16;
+   parameter shift = 1;
+   
+   input     clock;
+   input     reset;
+   input     enable;
+   input [bitwidth-1:0] xi,yi;
+   input [zwidth-1:0] zi;
+   input [zwidth-1:0] constant;
+   output [bitwidth-1:0] xo,yo;
+   output [zwidth-1:0] zo;
+   
+   wire z_is_pos = ~zi[zwidth-1];
+
+   reg [bitwidth-1:0] 	 xo,yo;
+   reg [zwidth-1:0] zo;
+   
+   always @(posedge clock)
+     if(reset)
+       begin
+	  xo <= 0;
+	  yo <= 0;
+	  zo <= 0;
+       end
+     else //if(enable)
+       begin
+	  xo <= z_is_pos ?   
+		xi - {{shift+1{yi[bitwidth-1]}},yi[bitwidth-2:shift]} :
+		xi + {{shift+1{yi[bitwidth-1]}},yi[bitwidth-2:shift]};
+	  yo <= z_is_pos ?   
+		yi + {{shift+1{xi[bitwidth-1]}},xi[bitwidth-2:shift]} :
+		yi - {{shift+1{xi[bitwidth-1]}},xi[bitwidth-2:shift]};
+	  zo <= z_is_pos ?   
+		zi - constant :
+		zi + constant;
+       end
+endmodule
diff --git a/usrp2/sdr_lib/cordic_z24.v b/usrp2/sdr_lib/cordic_z24.v
new file mode 100644
index 000000000..cf668d5ec
--- /dev/null
+++ b/usrp2/sdr_lib/cordic_z24.v
@@ -0,0 +1,126 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003, 2007 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+module cordic_z24(clock, reset, enable, xi, yi, zi, xo, yo, zo );
+   parameter bitwidth = 16;
+   parameter stages = 19;
+   localparam zwidth = 24;
+   
+   input clock;
+   input reset;
+   input enable;
+   input [bitwidth-1:0] xi, yi;
+   output [bitwidth-1:0] xo, yo;
+   input [zwidth-1:0] zi;
+   output [zwidth-1:0] zo;
+   
+   reg [bitwidth+1:0] 	 x0,y0;
+   reg [zwidth-2:0] 	 z0;
+   wire [bitwidth+1:0] 	 x1,x2,x3,x4,x5,x6,x7,x8,x9,x10,x11,x12,x13,x14,x15,x16,x17,x18,x19,x20;
+   wire [bitwidth+1:0] 	 y1,y2,y3,y4,y5,y6,y7,y8,y9,y10,y11,y12,y13,y14,y15,y16,y17,y18,y19,y20;
+   wire [zwidth-2:0] 	 z1,z2,z3,z4,z5,z6,z7,z8,z9,z10,z11,z12,z13,z14,z15,z16,z17,z18,z19,z20;
+   
+   wire [bitwidth+1:0] xi_ext = {{2{xi[bitwidth-1]}},xi};
+   wire [bitwidth+1:0] yi_ext = {{2{yi[bitwidth-1]}},yi};
+
+   // Compute consts.  Would be easier if vlog had atan...
+   // see gen_cordic_consts.py
+
+   // constants for 24 bit wide phase
+   localparam 	       c00 = 24'd2097152;
+   localparam 	       c01 = 24'd1238021;
+   localparam 	       c02 = 24'd654136;
+   localparam 	       c03 = 24'd332050;
+   localparam 	       c04 = 24'd166669;
+   localparam 	       c05 = 24'd83416;
+   localparam 	       c06 = 24'd41718;
+   localparam 	       c07 = 24'd20860;
+   localparam 	       c08 = 24'd10430;
+   localparam 	       c09 = 24'd5215;
+   localparam 	       c10 = 24'd2608;
+   localparam 	       c11 = 24'd1304;
+   localparam 	       c12 = 24'd652;
+   localparam 	       c13 = 24'd326;
+   localparam 	       c14 = 24'd163;
+   localparam 	       c15 = 24'd81;
+   localparam 	       c16 = 24'd41;
+   localparam 	       c17 = 24'd20;
+   localparam 	       c18 = 24'd10;
+   localparam 	       c19 = 24'd5;
+   localparam 	       c20 = 24'd3;
+   localparam 	       c21 = 24'd1;
+   localparam 	       c22 = 24'd1;
+   localparam 	       c23 = 24'd0;
+
+   always @(posedge clock)
+     if(reset)
+       begin
+	  x0   <= 0; y0   <= 0;  z0   <= 0;
+       end
+     else// if(enable)
+       begin
+	  z0 <= zi[zwidth-2:0];
+	  case (zi[zwidth-1:zwidth-2])
+	    2'b00, 2'b11 : 
+	      begin
+		 x0 <= xi_ext;
+		 y0 <= yi_ext;
+	      end
+	    2'b01, 2'b10 :
+	      begin
+		 x0 <= -xi_ext;
+		 y0 <= -yi_ext;
+	      end
+	  endcase // case(zi[zwidth-1:zwidth-2])
+       end // else: !if(reset)
+   
+   // FIXME need to handle variable number of stages
+   // This would be easier if arrays worked better in vlog...
+   
+   cordic_stage #(bitwidth+2,zwidth-1,0) cordic_stage0 (clock,reset,enable,x0,y0,z0,c00,x1,y1,z1);
+   cordic_stage #(bitwidth+2,zwidth-1,1) cordic_stage1 (clock,reset,enable,x1,y1,z1,c01,x2,y2,z2);
+   cordic_stage #(bitwidth+2,zwidth-1,2) cordic_stage2 (clock,reset,enable,x2,y2,z2,c02,x3,y3,z3);
+   cordic_stage #(bitwidth+2,zwidth-1,3) cordic_stage3 (clock,reset,enable,x3,y3,z3,c03,x4,y4,z4);
+   cordic_stage #(bitwidth+2,zwidth-1,4) cordic_stage4 (clock,reset,enable,x4,y4,z4,c04,x5,y5,z5);
+   cordic_stage #(bitwidth+2,zwidth-1,5) cordic_stage5 (clock,reset,enable,x5,y5,z5,c05,x6,y6,z6);
+   cordic_stage #(bitwidth+2,zwidth-1,6) cordic_stage6 (clock,reset,enable,x6,y6,z6,c06,x7,y7,z7);
+   cordic_stage #(bitwidth+2,zwidth-1,7) cordic_stage7 (clock,reset,enable,x7,y7,z7,c07,x8,y8,z8);
+   cordic_stage #(bitwidth+2,zwidth-1,8) cordic_stage8 (clock,reset,enable,x8,y8,z8,c08,x9,y9,z9);
+   cordic_stage #(bitwidth+2,zwidth-1,9) cordic_stage9 (clock,reset,enable,x9,y9,z9,c09,x10,y10,z10);
+   cordic_stage #(bitwidth+2,zwidth-1,10) cordic_stage10 (clock,reset,enable,x10,y10,z10,c10,x11,y11,z11);
+   cordic_stage #(bitwidth+2,zwidth-1,11) cordic_stage11 (clock,reset,enable,x11,y11,z11,c11,x12,y12,z12);
+   cordic_stage #(bitwidth+2,zwidth-1,12) cordic_stage12 (clock,reset,enable,x12,y12,z12,c12,x13,y13,z13);
+   cordic_stage #(bitwidth+2,zwidth-1,13) cordic_stage13 (clock,reset,enable,x13,y13,z13,c13,x14,y14,z14);
+   cordic_stage #(bitwidth+2,zwidth-1,14) cordic_stage14 (clock,reset,enable,x14,y14,z14,c14,x15,y15,z15);
+   cordic_stage #(bitwidth+2,zwidth-1,15) cordic_stage15 (clock,reset,enable,x15,y15,z15,c15,x16,y16,z16);
+   cordic_stage #(bitwidth+2,zwidth-1,16) cordic_stage16 (clock,reset,enable,x16,y16,z16,c16,x17,y17,z17);
+   cordic_stage #(bitwidth+2,zwidth-1,17) cordic_stage17 (clock,reset,enable,x17,y17,z17,c17,x18,y18,z18);
+   cordic_stage #(bitwidth+2,zwidth-1,18) cordic_stage18 (clock,reset,enable,x18,y18,z18,c18,x19,y19,z19);
+   cordic_stage #(bitwidth+2,zwidth-1,19) cordic_stage19 (clock,reset,enable,x19,y19,z19,c19,x20,y20,z20);
+
+   assign xo = x20[bitwidth:1];  
+   assign yo = y20[bitwidth:1];
+   assign zo = z20;		  
+   //assign xo = x20[bitwidth+1:2];  // CORDIC gain is ~1.6, plus gain from rotating vectors
+   //assign yo = y20[bitwidth+1:2];
+
+endmodule // cordic
+
diff --git a/usrp2/sdr_lib/ddc.v b/usrp2/sdr_lib/ddc.v
new file mode 100755
index 000000000..0d4da9bbc
--- /dev/null
+++ b/usrp2/sdr_lib/ddc.v
@@ -0,0 +1,97 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+
+
+// DDC block
+
+module ddc(input clock,
+			input reset,
+			input enable,
+			input [3:0] rate1,
+			input [3:0] rate2,
+			output strobe,
+			input [31:0] freq,
+			input [15:0] i_in,
+			input [15:0] q_in,
+			output [15:0] i_out,
+			output [15:0] q_out
+			);
+   parameter bw = 16;
+   parameter zw = 16;
+
+	wire [15:0] i_cordic_out, q_cordic_out;
+	wire [31:0] phase;
+
+	wire strobe1, strobe2;
+	reg [3:0] strobe_ctr1,strobe_ctr2;
+
+	always @(posedge clock)
+		if(reset | ~enable)
+			strobe_ctr2 <= #1 4'd0;
+		else if(strobe2)
+			strobe_ctr2 <= #1 4'd0;
+		else	
+			strobe_ctr2 <= #1 strobe_ctr2 + 4'd1;
+				
+	always @(posedge clock)
+		if(reset | ~enable)
+			strobe_ctr1 <= #1 4'd0;
+		else if(strobe1)
+			strobe_ctr1 <= #1 4'd0;
+		else if(strobe2)
+			strobe_ctr1 <= #1 strobe_ctr1 + 4'd1;
+				
+
+	assign strobe2 = enable & ( strobe_ctr2 == rate2 );
+	assign strobe1 = strobe2 & ( strobe_ctr1 == rate1 );
+
+	assign strobe = strobe1;
+
+	function [2:0] log_ceil;
+	input [3:0] val;
+	
+		log_ceil = val[3] ? 3'd4 : val[2] ? 3'd3 : val[1] ? 3'd2 : 3'd1; 
+	endfunction	
+	
+	wire [2:0] shift1 = log_ceil(rate1);
+	wire [2:0] shift2 = log_ceil(rate2);
+	
+	cordic #(.bitwidth(bw),.zwidth(zw),.stages(16))
+		cordic(.clock(clock), .reset(reset), .enable(enable),
+			.xi(i_in), .yi(q_in), .zi(phase[31:32-zw]), 
+			.xo(i_cordic_out), .yo(q_cordic_out), .zo()  );
+		
+	cic_decim_2stage #(.bw(bw),.N(4)) 
+		decim_i(.clock(clock),.reset(reset),.enable(enable),
+			.strobe1(1'b1),.strobe2(strobe2),.strobe3(strobe1),.shift1(shift2),.shift2(shift1),
+			.signal_in(i_cordic_out),.signal_out(i_out));
+			
+	cic_decim_2stage #(.bw(bw),.N(4)) 
+		decim_q(.clock(clock),.reset(reset),.enable(enable),
+			.strobe1(1'b1),.strobe2(strobe2),.strobe3(strobe1),.shift1(shift2),.shift2(shift1),
+			.signal_in(q_cordic_out),.signal_out(q_out));
+	
+	phase_acc #(.resolution(32))
+		nco (.clk(clock),.reset(reset),.enable(enable),
+			.freq(freq),.phase(phase));
+		
+endmodule
diff --git a/usrp2/sdr_lib/dsp_core_rx.v b/usrp2/sdr_lib/dsp_core_rx.v
new file mode 100644
index 000000000..af4f0b9fb
--- /dev/null
+++ b/usrp2/sdr_lib/dsp_core_rx.v
@@ -0,0 +1,179 @@
+
+`define DSP_CORE_RX_BASE 160
+module dsp_core_rx
+  (input clk, input rst,
+   input set_stb, input [7:0] set_addr, input [31:0] set_data,
+
+   input [13:0] adc_a, input adc_ovf_a,
+   input [13:0] adc_b, input adc_ovf_b,
+   
+   input [15:0] io_rx,
+
+   output [31:0] sample,
+   input run,
+   output strobe,
+   output [31:0] debug
+   );
+
+   wire [15:0] scale_i, scale_q;
+   wire [13:0] adc_a_ofs, adc_b_ofs;
+   reg [13:0] adc_i, adc_q;
+   wire [31:0] phase_inc;
+   reg [31:0]  phase;
+
+   wire [35:0] prod_i, prod_q;
+   wire [23:0] i_cordic, q_cordic;
+   wire [23:0] i_cic, q_cic;
+   wire [17:0] i_cic_scaled, q_cic_scaled;
+   wire [17:0] i_hb1, q_hb1;
+   wire [17:0] i_hb2, q_hb2;
+   wire [15:0] i_out, q_out;
+
+   wire        strobe_cic, strobe_hb1, strobe_hb2;
+   wire        enable_hb1, enable_hb2;
+   wire [7:0]  cic_decim_rate;
+   
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+0)) sr_0
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(phase_inc),.changed());
+   
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+1)) sr_1
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out({scale_i,scale_q}),.changed());
+   
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+2)) sr_2
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out({enable_hb1, enable_hb2, cic_decim_rate}),.changed());
+
+   rx_dcoffset #(.WIDTH(14),.ADDR(`DSP_CORE_RX_BASE+6)) rx_dcoffset_a
+     (.clk(clk),.rst(rst),.set_stb(set_stb),.set_addr(set_addr),.set_data(set_data),
+      .adc_in(adc_a),.adc_out(adc_a_ofs));
+   
+   rx_dcoffset #(.WIDTH(14),.ADDR(`DSP_CORE_RX_BASE+7)) rx_dcoffset_b
+     (.clk(clk),.rst(rst),.set_stb(set_stb),.set_addr(set_addr),.set_data(set_data),
+      .adc_in(adc_b),.adc_out(adc_b_ofs));
+
+   wire [3:0]  muxctrl;
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+8)) sr_8
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(muxctrl),.changed());
+
+   wire [1:0] gpio_ena;
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+9)) sr_9
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(gpio_ena),.changed());
+
+   // The TVRX connects to what is called adc_b, thus A and B are
+   // swapped throughout the design.
+   //
+   // In the interest of expediency and keeping the s/w sane, we just remap them here.
+   // The I & Q fields are mapped the same:
+   // 0 -> "the real A" (as determined by the TVRX)
+   // 1 -> "the real B"
+   // 2 -> const zero
+   
+   always @(posedge clk)
+     case(muxctrl[1:0])		// The I mapping
+       0: adc_i <= adc_b_ofs;	// "the real A"
+       1: adc_i <= adc_a_ofs;
+       2: adc_i <= 0;
+       default: adc_i <= 0;
+     endcase // case(muxctrl[1:0])
+          
+   always @(posedge clk)
+     case(muxctrl[3:2])		// The Q mapping
+       0: adc_q <= adc_b_ofs;	// "the real A"
+       1: adc_q <= adc_a_ofs;
+       2: adc_q <= 0;
+       default: adc_q <= 0;
+     endcase // case(muxctrl[3:2])
+       
+   always @(posedge clk)
+     if(rst)
+       phase <= 0;
+     else if(~run)
+       phase <= 0;
+     else
+       phase <= phase + phase_inc;
+
+   MULT18X18S mult_i
+     (.P(prod_i),    // 36-bit multiplier output
+      .A({{4{adc_i[13]}},adc_i} ),    // 18-bit multiplier input
+      .B({{2{scale_i[15]}},scale_i}),    // 18-bit multiplier input
+      .C(clk),    // Clock input
+      .CE(1),  // Clock enable input
+      .R(rst)     // Synchronous reset input
+      );
+
+   MULT18X18S mult_q
+     (.P(prod_q),    // 36-bit multiplier output
+      .A({{4{adc_q[13]}},adc_q} ),    // 18-bit multiplier input
+      .B({{2{scale_q[15]}},scale_q}),    // 18-bit multiplier input
+      .C(clk),    // Clock input
+      .CE(1),  // Clock enable input
+      .R(rst)     // Synchronous reset input
+      ); 
+
+   
+   cordic_z24 #(.bitwidth(24))
+     cordic(.clock(clk), .reset(rst), .enable(run),
+	    .xi(prod_i[23:0]),. yi(prod_q[23:0]), .zi(phase[31:8]),
+	    .xo(i_cordic),.yo(q_cordic),.zo() );
+
+   cic_strober cic_strober(.clock(clk),.reset(rst),.enable(run),.rate(cic_decim_rate),
+			   .strobe_fast(1),.strobe_slow(strobe_cic) );
+
+   cic_decim #(.bw(24))
+     decim_i (.clock(clk),.reset(rst),.enable(run),
+	      .rate(cic_decim_rate),.strobe_in(1'b1),.strobe_out(strobe_cic),
+	      .signal_in(i_cordic),.signal_out(i_cic));
+   
+   cic_decim #(.bw(24))
+     decim_q (.clock(clk),.reset(rst),.enable(run),
+	      .rate(cic_decim_rate),.strobe_in(1'b1),.strobe_out(strobe_cic),
+	      .signal_in(q_cordic),.signal_out(q_cic));
+
+   round_reg #(.bits_in(24),.bits_out(18)) round_icic (.clk(clk),.in(i_cic),.out(i_cic_scaled));
+   round_reg #(.bits_in(24),.bits_out(18)) round_qcic (.clk(clk),.in(q_cic),.out(q_cic_scaled));
+   reg 	       strobe_cic_d1;
+   always @(posedge clk) strobe_cic_d1 <= strobe_cic;
+   
+   small_hb_dec #(.WIDTH(18)) small_hb_i
+     (.clk(clk),.rst(rst),.bypass(~enable_hb1),.run(run),
+      .stb_in(strobe_cic_d1),.data_in(i_cic_scaled),.stb_out(strobe_hb1),.data_out(i_hb1));
+   
+   small_hb_dec #(.WIDTH(18)) small_hb_q
+     (.clk(clk),.rst(rst),.bypass(~enable_hb1),.run(run),
+      .stb_in(strobe_cic_d1),.data_in(q_cic_scaled),.stb_out(),.data_out(q_hb1));
+
+   wire [8:0]  cpi_hb = enable_hb1 ? {cic_decim_rate,1'b0} : {1'b0,cic_decim_rate};
+   hb_dec #(.IWIDTH(18), .OWIDTH(18), .CWIDTH(18), .ACCWIDTH(24)) hb_i
+     (.clk(clk),.rst(rst),.bypass(~enable_hb2),.run(run),.cpi(cpi_hb),
+      .stb_in(strobe_hb1),.data_in(i_hb1),.stb_out(strobe_hb2),.data_out(i_hb2));
+
+   hb_dec #(.IWIDTH(18), .OWIDTH(18), .CWIDTH(18), .ACCWIDTH(24)) hb_q
+     (.clk(clk),.rst(rst),.bypass(~enable_hb2),.run(run),.cpi(cpi_hb),
+      .stb_in(strobe_hb1),.data_in(q_hb1),.stb_out(),.data_out(q_hb2));
+
+   round #(.bits_in(18),.bits_out(16)) round_iout (.in(i_hb2),.out(i_out));
+   round #(.bits_in(18),.bits_out(16)) round_qout (.in(q_hb2),.out(q_out));
+
+   // Streaming GPIO
+   //
+   // io_rx[15] => I channel LSB if gpio_ena[0] high
+   // io_rx[14] => Q channel LSB if gpio_ena[1] high
+
+   reg [31:0] sample_reg;
+   always @(posedge clk)
+     begin
+	sample_reg[31:17] <= i_out[15:1];
+	sample_reg[15:1]  <= q_out[15:1];
+	sample_reg[16]    <= gpio_ena[0] ? io_rx[15] : i_out[0]; 
+	sample_reg[0]     <= gpio_ena[1] ? io_rx[14] : q_out[0];
+     end
+   
+   assign      sample = sample_reg;
+   assign      strobe = strobe_hb2;
+   assign      debug = {enable_hb1, enable_hb2, run, strobe, strobe_cic, strobe_cic_d1, strobe_hb1, strobe_hb2};
+   
+endmodule // dsp_core_rx
diff --git a/usrp2/sdr_lib/dsp_core_tx.v b/usrp2/sdr_lib/dsp_core_tx.v
new file mode 100644
index 000000000..346d65ced
--- /dev/null
+++ b/usrp2/sdr_lib/dsp_core_tx.v
@@ -0,0 +1,152 @@
+
+`define DSP_CORE_TX_BASE 128
+
+module dsp_core_tx
+  (input clk, input rst,
+   input set_stb, input [7:0] set_addr, input [31:0] set_data,
+
+   output reg [15:0] dac_a,
+   output reg [15:0] dac_b,
+
+   // To tx_control
+   input [31:0] sample,
+   input run,
+   output strobe,
+   output [31:0] debug
+   );
+
+   wire [15:0] i, q, scale_i, scale_q;
+   wire [31:0] phase_inc;
+   reg [31:0]  phase;
+   wire [7:0]  interp_rate;
+   wire [3:0]  dacmux_a, dacmux_b;
+   wire        enable_hb1, enable_hb2;
+
+   setting_reg #(.my_addr(`DSP_CORE_TX_BASE+0)) sr_0
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(phase_inc),.changed());
+
+   setting_reg #(.my_addr(`DSP_CORE_TX_BASE+1)) sr_1
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out({scale_i,scale_q}),.changed());
+   
+   setting_reg #(.my_addr(`DSP_CORE_TX_BASE+2)) sr_2
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out({enable_hb1, enable_hb2, interp_rate}),.changed());
+
+   setting_reg #(.my_addr(`DSP_CORE_TX_BASE+4)) sr_4
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out({dacmux_b,dacmux_a}),.changed());
+
+   // Strobes are all now delayed by 1 cycle for timing reasons
+   wire        strobe_cic_pre, strobe_hb1_pre, strobe_hb2_pre;
+   reg 	       strobe_cic = 1;
+   reg 	       strobe_hb1 = 1;
+   reg 	       strobe_hb2 = 1;
+   
+   cic_strober #(.WIDTH(8))
+     cic_strober(.clock(clk),.reset(rst),.enable(run),.rate(interp_rate),
+		 .strobe_fast(1),.strobe_slow(strobe_cic_pre) );
+   cic_strober #(.WIDTH(2))
+     hb2_strober(.clock(clk),.reset(rst),.enable(run),.rate(enable_hb2 ? 2 : 1),
+		 .strobe_fast(strobe_cic_pre),.strobe_slow(strobe_hb2_pre) );
+   cic_strober #(.WIDTH(2))
+     hb1_strober(.clock(clk),.reset(rst),.enable(run),.rate(enable_hb1 ? 2 : 1),
+		 .strobe_fast(strobe_hb2_pre),.strobe_slow(strobe_hb1_pre) );
+   
+   always @(posedge clk) strobe_hb1 <= strobe_hb1_pre;
+   always @(posedge clk) strobe_hb2 <= strobe_hb2_pre;
+   always @(posedge clk) strobe_cic <= strobe_cic_pre;
+
+   // NCO
+   always @(posedge clk)
+     if(rst)
+       phase <= 0;
+     else if(~run)
+       phase <= 0;
+     else
+       phase <= phase + phase_inc;
+   
+   wire        signed [17:0] da, db;
+   wire        signed [35:0] prod_i, prod_q;
+
+   wire [17:0] bb_i = {sample[31:16],2'b0};
+   wire [17:0] bb_q = {sample[15:0],2'b0};
+   wire [17:0] i_interp, q_interp;
+
+   wire [17:0] hb1_i, hb1_q, hb2_i, hb2_q;
+
+   wire [7:0]  cpo = enable_hb2 ? ({interp_rate,1'b0}) : interp_rate;
+   // Note that max CIC rate is 128, which would give an overflow on cpo if enable_hb2 is true,
+   //   but the default case inside hb_interp handles this
+   
+   hb_interp #(.IWIDTH(18),.OWIDTH(18),.ACCWIDTH(24)) hb_interp_i
+     (.clk(clk),.rst(rst),.bypass(~enable_hb1),.cpo(cpo),.stb_in(strobe_hb1),.data_in(bb_i),.stb_out(strobe_hb2),.data_out(hb1_i));
+   hb_interp #(.IWIDTH(18),.OWIDTH(18),.ACCWIDTH(24)) hb_interp_q
+     (.clk(clk),.rst(rst),.bypass(~enable_hb1),.cpo(cpo),.stb_in(strobe_hb1),.data_in(bb_q),.stb_out(strobe_hb2),.data_out(hb1_q));
+   
+   small_hb_int #(.WIDTH(18)) small_hb_interp_i
+     (.clk(clk),.rst(rst),.bypass(~enable_hb2),.stb_in(strobe_hb2),.data_in(hb1_i),
+      .output_rate(interp_rate),.stb_out(strobe_cic),.data_out(hb2_i));
+   small_hb_int #(.WIDTH(18)) small_hb_interp_q
+     (.clk(clk),.rst(rst),.bypass(~enable_hb2),.stb_in(strobe_hb2),.data_in(hb1_q),
+      .output_rate(interp_rate),.stb_out(strobe_cic),.data_out(hb2_q));
+   
+   cic_interp  #(.bw(18),.N(4),.log2_of_max_rate(7))
+     cic_interp_i(.clock(clk),.reset(rst),.enable(run),.rate(interp_rate),
+		  .strobe_in(strobe_cic),.strobe_out(1),
+		  .signal_in(hb2_i),.signal_out(i_interp));
+   
+   cic_interp  #(.bw(18),.N(4),.log2_of_max_rate(7))
+     cic_interp_q(.clock(clk),.reset(rst),.enable(run),.rate(interp_rate),
+		  .strobe_in(strobe_cic),.strobe_out(1),
+		  .signal_in(hb2_q),.signal_out(q_interp));
+
+   assign      strobe = strobe_hb1;
+
+   localparam  cwidth = 24;  // was 18
+   localparam  zwidth = 24;  // was 16
+
+   wire [cwidth-1:0] da_c, db_c;
+   
+   cordic_z24 #(.bitwidth(cwidth))
+     cordic(.clock(clk), .reset(rst), .enable(run),
+	    .xi({i_interp,{(cwidth-18){1'b0}}}),.yi({q_interp,{(cwidth-18){1'b0}}}),
+	    .zi(phase[31:32-zwidth]),
+	    .xo(da_c),.yo(db_c),.zo() );
+   
+   MULT18X18S MULT18X18S_inst 
+     (.P(prod_i),    // 36-bit multiplier output
+      .A(da_c[cwidth-1:cwidth-18]),    // 18-bit multiplier input
+      .B({{2{scale_i[15]}},scale_i}),    // 18-bit multiplier input
+      .C(clk),    // Clock input
+      .CE(1),  // Clock enable input
+      .R(rst)     // Synchronous reset input
+      );
+   
+   MULT18X18S MULT18X18S_inst_2 
+     (.P(prod_q),    // 36-bit multiplier output
+      .A(db_c[cwidth-1:cwidth-18]),    // 18-bit multiplier input
+      .B({{2{scale_q[15]}},scale_q}),    // 18-bit multiplier input
+      .C(clk),    // Clock input
+      .CE(1),  // Clock enable input
+      .R(rst)     // Synchronous reset input
+      );
+   
+   always @(posedge clk)
+     case(dacmux_a)
+       0 : dac_a <= prod_i[28:13];
+       1 : dac_a <= prod_q[28:13];
+       default : dac_a <= 0;
+     endcase // case(dacmux_a)
+   
+   always @(posedge clk)
+     case(dacmux_b)
+       0 : dac_b <= prod_i[28:13];
+       1 : dac_b <= prod_q[28:13];
+       default : dac_b <= 0;
+     endcase // case(dacmux_b)
+   
+   assign      debug = {strobe_cic, strobe_hb1, strobe_hb2,run};
+
+endmodule // dsp_core
diff --git a/usrp2/sdr_lib/duc.v b/usrp2/sdr_lib/duc.v
new file mode 100755
index 000000000..6dac95b49
--- /dev/null
+++ b/usrp2/sdr_lib/duc.v
@@ -0,0 +1,95 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+// DUC block
+
+module duc(input clock,
+			input reset,
+			input enable,
+			input [3:0] rate1,
+			input [3:0] rate2,
+			output strobe,
+			input [31:0] freq,
+			input [15:0] i_in,
+			input [15:0] q_in,
+			output [15:0] i_out,
+			output [15:0] q_out
+			);
+   parameter bw = 16;
+   parameter zw = 16;
+   
+	wire [15:0] i_interp_out, q_interp_out;
+	wire [31:0] phase;
+
+	wire strobe1, strobe2;
+	reg [3:0] strobe_ctr1,strobe_ctr2;
+
+	always @(posedge clock)
+		if(reset | ~enable)
+			strobe_ctr2 <= #1 4'd0;
+		else if(strobe2)
+			strobe_ctr2 <= #1 4'd0;
+		else	
+			strobe_ctr2 <= #1 strobe_ctr2 + 4'd1;
+				
+	always @(posedge clock)
+		if(reset | ~enable)
+			strobe_ctr1 <= #1 4'd0;
+		else if(strobe1)
+			strobe_ctr1 <= #1 4'd0;
+		else if(strobe2)
+			strobe_ctr1 <= #1 strobe_ctr1 + 4'd1;
+				
+
+	assign strobe2 = enable & ( strobe_ctr2 == rate2 );
+	assign strobe1 = strobe2 & ( strobe_ctr1 == rate1 );
+
+	assign strobe = strobe1;
+
+	function [2:0] log_ceil;
+	input [3:0] val;
+	
+		log_ceil = val[3] ? 3'd4 : val[2] ? 3'd3 : val[1] ? 3'd2 : 3'd1; 
+	endfunction	
+	
+	wire [2:0] shift1 = log_ceil(rate1);
+	wire [2:0] shift2 = log_ceil(rate2);
+	
+	cordic #(.bitwidth(bw),.zwidth(zw),.stages(16))
+		cordic(.clock(clock), .reset(reset), .enable(enable),
+			.xi(i_interp_out), .yi(q_interp_out), .zi(phase[31:32-zw]), 
+			.xo(i_out), .yo(q_out), .zo()  );
+		
+	cic_interp_2stage #(.bw(bw),.N(4)) 
+		interp_i(.clock(clock),.reset(reset),.enable(enable),
+			.strobe1(strobe1),.strobe2(strobe2),.strobe3(1'b1),.shift1(shift1),.shift2(shift2),
+			.signal_in(i_in),.signal_out(i_interp_out));
+
+	cic_interp_2stage #(.bw(bw),.N(4)) 
+		interp_q(.clock(clock),.reset(reset),.enable(enable),
+			.strobe1(strobe1),.strobe2(strobe2),.strobe3(1'b1),.shift1(shift1),.shift2(shift2),
+			.signal_in(q_in),.signal_out(q_interp_out));
+	
+	phase_acc #(.resolution(32))
+		nco (.clk(clock),.reset(reset),.enable(enable),
+			.freq(freq),.phase(phase));
+		
+endmodule
diff --git a/usrp2/sdr_lib/dummy_rx.v b/usrp2/sdr_lib/dummy_rx.v
new file mode 100644
index 000000000..99290ecec
--- /dev/null
+++ b/usrp2/sdr_lib/dummy_rx.v
@@ -0,0 +1,62 @@
+
+`define DSP_CORE_RX_BASE 160
+module dummy_rx
+  (input clk, input rst,
+   input set_stb, input [7:0] set_addr, input [31:0] set_data,
+
+   input [13:0] adc_a, input adc_ovf_a,
+   input [13:0] adc_b, input adc_ovf_b,
+   
+   output [31:0] sample,
+   input run,
+   output strobe
+   );
+
+   wire [15:0] scale_i, scale_q;
+   wire [31:0] phase_inc;
+   reg [31:0]  phase;
+
+   wire [23:0] i_decim, q_decim;
+   wire [7:0]  decim_rate;
+   
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+0)) sr_0
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(phase_inc),.changed());
+   
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+1)) sr_1
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out({scale_i,scale_q}),.changed());
+   
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+2)) sr_2
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(decim_rate),.changed());
+   
+   strobe_gen strobe_gen(.clock(clk),.reset(rst),.enable(run),.rate(decim_rate),
+			 .strobe_in(1),.strobe(strobe) );
+
+   reg [15:0] i_out, q_out;
+   assign      sample = {i_out,q_out};
+
+   always @(posedge clk)
+     if(rst)
+       i_out <= 0;
+     else if(~run)
+       i_out <= 0;
+     else if(strobe)
+       i_out <= i_out + 1;
+
+   reg 	       run_d1;
+   always @(posedge clk)
+     if(rst)
+       run_d1 <= 0;
+     else
+       run_d1 <= run;
+
+   always @(posedge clk)
+     if(rst)
+       q_out <= 0;
+     else if (run & ~run_d1)
+       q_out <= q_out + 1;
+       
+   
+endmodule // dsp_core_rx
diff --git a/usrp2/sdr_lib/gen_cordic_consts.py b/usrp2/sdr_lib/gen_cordic_consts.py
new file mode 100755
index 000000000..261e8c223
--- /dev/null
+++ b/usrp2/sdr_lib/gen_cordic_consts.py
@@ -0,0 +1,10 @@
+#!/usr/bin/env python
+
+import math
+
+zwidth = 24
+
+for i in range(24):
+    c = math.atan (1.0/(2**i)) / (2 * math.pi) * (1 << zwidth)
+    print "localparam c%02d = %d'd%d;" % (i, zwidth, round (c))
+    
diff --git a/usrp2/sdr_lib/halfband_ideal.v b/usrp2/sdr_lib/halfband_ideal.v
new file mode 100644
index 000000000..484cfff2a
--- /dev/null
+++ b/usrp2/sdr_lib/halfband_ideal.v
@@ -0,0 +1,84 @@
+module halfband_ideal (
+    input                           clock,
+    input                           reset,
+    input                           enable,
+    input                           strobe_in,
+    input   wire    signed  [17:0]  data_in,
+    output  reg                     strobe_out,
+    output  reg     signed  [17:0]  data_out
+) ;
+
+    parameter                       decim   = 1 ;
+    parameter                       rate    = 2 ;
+
+    reg signed              [40:0]  temp ;
+    reg signed              [17:0]  delay[30:0] ;
+    reg signed              [17:0]  coeffs[30:0] ;
+    reg                     [7:0]   count ;
+    integer                         i ;
+
+    initial begin
+        for( i = 0 ; i < 31 ; i = i + 1 ) begin
+            coeffs[i] = 18'd0 ;
+        end
+        coeffs[0]   = -1390 ;
+        coeffs[2]   = 1604 ;
+        coeffs[4]   = -1896 ;
+        coeffs[6]   = 2317 ;
+        coeffs[8]   = -2979 ;
+        coeffs[10]  = 4172 ;
+        coeffs[12]  = -6953 ;
+        coeffs[14]  = 20860 ;
+        coeffs[15]  = 32768 ;
+        coeffs[16]  = 20860 ;
+        coeffs[18]  = -6953 ;
+        coeffs[20]  = 4172 ;
+        coeffs[22]  = -2979 ;
+        coeffs[24]  = 2317 ;
+        coeffs[26]  = -1896 ;
+        coeffs[28]  = 1604 ;
+        coeffs[30]  = -1390 ;
+    end
+
+    always @(posedge clock) begin
+        if( reset ) begin
+            count <= 0 ;
+            for( i = 0 ; i < 31 ; i = i + 1 ) begin
+                delay[i] <= 18'd0 ;
+            end
+            temp        <= 41'd0 ;
+            data_out    <= 18'd0 ;
+            strobe_out  <= 1'b0 ;
+        end else if( enable ) begin
+
+            if( (decim && (count == rate-1)) || !decim ) 
+                strobe_out <= strobe_in ;
+            else
+                strobe_out <= 1'b0 ;
+            
+
+            if( strobe_in ) begin
+                // Increment decimation count
+                count <= count + 1 ;
+
+                // Shift the input
+                for( i = 30 ; i > 0 ; i = i - 1 ) begin
+                    delay[i] = delay[i-1] ;
+                end
+                delay[0] = data_in ;
+
+                // clear the temp reg
+                temp = 18'd0 ;
+                if( (decim && (count == rate-1)) || !decim ) begin
+                    count <= 0 ;
+                    for( i = 0 ; i < 31 ; i = i + 1 ) begin
+                        // Multiply Accumulate
+                        temp = temp + delay[i]*coeffs[i] ;
+                    end
+                    // Assign data output
+                    data_out <= temp >>> 15 ;
+                end
+            end
+        end
+    end
+endmodule
diff --git a/usrp2/sdr_lib/halfband_tb.v b/usrp2/sdr_lib/halfband_tb.v
new file mode 100644
index 000000000..231dd00d7
--- /dev/null
+++ b/usrp2/sdr_lib/halfband_tb.v
@@ -0,0 +1,120 @@
+module halfband_tb( ) ;
+    
+    // Parameters for instantiation
+    parameter               clocks  = 2 ; // Number of clocks per input
+    parameter               decim   = 0 ; // Sets the filter to decimate
+    parameter               rate    = 2 ; // Sets the decimation rate
+
+    reg                     clock ;
+    reg                     reset ;
+    reg                     enable ;
+    reg                     strobe_in ;
+    reg     signed  [17:0]  data_in ;
+    wire                    strobe_out ;
+    wire    signed  [17:0]  data_out ;
+
+    // Setup the clock
+    initial clock = 1'b0 ;
+    always #5 clock <= ~clock ;
+
+    // Come out of reset after a while
+    initial reset = 1'b1 ;
+    initial #100 reset = 1'b0 ;
+
+    // Enable the entire system
+    initial enable = 1'b1 ;
+
+    // Instantiate UUT
+    halfband_ideal 
+      #(
+        .decim      ( decim         ),
+        .rate       ( rate          )
+      ) uut(
+        .clock      ( clock         ),
+        .reset      ( reset         ),
+        .enable     ( enable        ),
+        .strobe_in  ( strobe_in     ),
+        .data_in    ( data_in       ),
+        .strobe_out ( strobe_out    ),
+        .data_out   ( data_out      )
+      ) ;
+    
+    integer i, ri, ro, infile, outfile ;
+
+    // Setup file IO
+    initial begin
+        infile = $fopen("input.dat","r") ;
+        outfile = $fopen("output.dat","r") ;
+        $timeformat(-9, 2, " ns", 10) ;
+    end
+
+    reg                 endofsim ;
+    reg signed  [17:0]  compare ;
+    integer             noe ;
+    initial             noe = 0 ;
+
+    initial begin
+        // Initialize inputs
+        strobe_in <= 1'd0 ;
+        data_in <= 18'd0 ;
+
+        // Wait for reset to go away
+        @(negedge reset) #0 ;
+        
+        // While we're still simulating ...
+        while( !endofsim ) begin
+
+            // Write the input from the file or 0 if EOF...
+            @( posedge clock ) begin
+                #1 ;
+                strobe_in <= 1'b1 ;
+                if( !$feof(infile) )
+                    ri = $fscanf( infile, "%d", data_in ) ;
+                else
+                    data_in <= 18'd0 ;
+            end
+
+            // Clocked in - set the strobe to 0 if the number of
+            // clocks per sample is greater than 1
+            if( clocks > 1 ) begin
+                @(posedge clock) begin
+                    strobe_in <= 1'b0  ;
+                end
+
+                // Wait for the specified number of cycles
+                for( i = 0 ; i < (clocks-2) ; i = i + 1 ) begin
+                    @(posedge clock) #1 ;
+                end
+            end
+        end
+
+        // Print out the number of errors that occured
+        if( noe )
+            $display( "FAILED: %d errors during simulation", noe ) ;
+        else
+            $display( "PASSED: Simulation successful" ) ;
+
+        $stop ;
+    end
+
+    // Output comparison of simulated values versus known good values
+    always @ (posedge clock) begin
+        if( reset )
+            endofsim <= 1'b0 ;
+        else begin
+            if( !$feof(outfile) ) begin
+                if( strobe_out ) begin
+                    ro = $fscanf( outfile, "%d\n", compare ) ;
+                    if( compare != data_out ) begin
+                        $display( "%t: %d != %d", $realtime, data_out, compare ) ;
+                        noe = noe + 1 ;
+                    end
+                end
+            end else begin
+                // Signal end of simulation when no more outputs
+                endofsim <= 1'b1 ;
+            end
+        end
+    end     
+
+endmodule
diff --git a/usrp2/sdr_lib/hb/acc.v b/usrp2/sdr_lib/hb/acc.v
new file mode 100644
index 000000000..195d5ea94
--- /dev/null
+++ b/usrp2/sdr_lib/hb/acc.v
@@ -0,0 +1,22 @@
+
+
+module acc (input clock, input reset, input clear, input enable_in, output reg enable_out,
+	    input signed [30:0] addend, output reg signed [33:0] sum );
+
+   always @(posedge clock)
+     if(reset)
+       sum <= #1 34'd0;
+     //else if(clear & enable_in)
+     //  sum <= #1 addend;
+     //else if(clear)
+     //  sum <= #1 34'd0;
+     else if(clear)
+       sum <= #1 addend;
+     else if(enable_in)
+       sum <= #1 sum + addend;
+
+   always @(posedge clock)
+     enable_out <= #1 enable_in;
+   
+endmodule // acc
+
diff --git a/usrp2/sdr_lib/hb/coeff_ram.v b/usrp2/sdr_lib/hb/coeff_ram.v
new file mode 100644
index 000000000..65460822f
--- /dev/null
+++ b/usrp2/sdr_lib/hb/coeff_ram.v
@@ -0,0 +1,26 @@
+
+
+module coeff_ram (input clock, input [3:0] rd_addr, output reg [15:0] rd_data);
+
+   always @(posedge clock)
+     case (rd_addr)
+       4'd0 : rd_data <= #1 -16'd16;
+       4'd1 : rd_data <= #1 16'd74;
+       4'd2 : rd_data <= #1 -16'd254;
+       4'd3 : rd_data <= #1 16'd669;
+       4'd4 : rd_data <= #1 -16'd1468;
+       4'd5 : rd_data <= #1 16'd2950;
+       4'd6 : rd_data <= #1 -16'd6158;
+       4'd7 : rd_data <= #1 16'd20585;
+       4'd8 : rd_data <= #1 16'd20585;
+       4'd9 : rd_data <= #1 -16'd6158;
+       4'd10 : rd_data <= #1 16'd2950;
+       4'd11 : rd_data <= #1 -16'd1468;
+       4'd12 : rd_data <= #1 16'd669;
+       4'd13 : rd_data <= #1 -16'd254;
+       4'd14 : rd_data <= #1 16'd74;
+       4'd15 : rd_data <= #1 -16'd16;
+       default : rd_data <= #1 16'd0;
+     endcase // case(rd_addr)
+   
+endmodule // ram
diff --git a/usrp2/sdr_lib/hb/coeff_rom.v b/usrp2/sdr_lib/hb/coeff_rom.v
new file mode 100644
index 000000000..7f8886b4e
--- /dev/null
+++ b/usrp2/sdr_lib/hb/coeff_rom.v
@@ -0,0 +1,19 @@
+
+
+module coeff_rom (input clock, input [2:0] addr, output reg [15:0] data);
+
+   always @(posedge clock)
+     case (addr)
+       3'd0 : data <= #1 -16'd49;
+       3'd1 : data <= #1 16'd165;
+       3'd2 : data <= #1 -16'd412;
+       3'd3 : data <= #1 16'd873;
+       3'd4 : data <= #1 -16'd1681;
+       3'd5 : data <= #1 16'd3135;
+       3'd6 : data <= #1 -16'd6282;
+       3'd7 : data <= #1 16'd20628;
+     endcase // case(addr)
+      
+endmodule // coeff_rom
+
+
diff --git a/usrp2/sdr_lib/hb/halfband_decim.v b/usrp2/sdr_lib/hb/halfband_decim.v
new file mode 100644
index 000000000..dff4d902c
--- /dev/null
+++ b/usrp2/sdr_lib/hb/halfband_decim.v
@@ -0,0 +1,163 @@
+/* -*- verilog -*-
+ * 
+ *  USRP - Universal Software Radio Peripheral
+ * 
+ *  Copyright (C) 2005 Matt Ettus
+ * 
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ * 
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ * 
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+ */
+
+/*
+ * This implements a 31-tap halfband filter that decimates by two.
+ * The coefficients are symmetric, and with the exception of the middle tap,
+ * every other coefficient is zero.  The middle section of taps looks like this:
+ *
+ *  ..., -1468, 0, 2950, 0, -6158, 0, 20585, 32768, 20585, 0, -6158, 0, 2950, 0, -1468, ...
+ *                                             |
+ *                           middle tap -------+
+ *
+ * See coeff_rom.v for the full set.  The taps are scaled relative to 32768,
+ * thus the middle tap equals 1.0.  Not counting the middle tap, there are 8
+ * non-zero taps on each side, and they are symmetric.  A naive implementation
+ * requires a mulitply for each non-zero tap.  Because of symmetry, we can
+ * replace 2 multiplies with 1 add and 1 multiply.  Thus, to compute each output
+ * sample, we need to perform 8 multiplications.  Since the middle tap is 1.0,
+ * we just add the corresponding delay line value.
+ *
+ * About timing: We implement this with a single multiplier, so it takes
+ * 8 cycles to compute a single output.  However, since we're decimating by two 
+ * we can accept a new input value every 4 cycles.  strobe_in is asserted when
+ * there's a new input sample available.  Depending on the overall decimation
+ * rate, strobe_in may be asserted less frequently than once every 4 clocks.
+ * On the output side, we assert strobe_out when output contains a new sample.
+ *
+ * Implementation: Every time strobe_in is asserted we store the new data into
+ * the delay line.  We split the delay line into two components, one for the
+ * even samples, and one for the odd samples.  ram16_odd is the delay line for
+ * the odd samples.  This ram is written on each odd assertion of strobe_in, and
+ * is read on each clock when we're computing the dot product.  ram16_even is
+ * similar, although because it holds the even samples we must be able to read
+ * two samples from different addresses at the same time, while writing the incoming
+ * even samples. Thus it's "triple-ported".
+ */
+
+module halfband_decim
+  (input clock, input reset, input enable, input strobe_in, output wire strobe_out,
+   input wire [15:0] data_in, output reg [15:0] data_out,output wire [15:0] debugctrl);
+
+   reg [3:0] rd_addr1;
+   reg [3:0] rd_addr2;
+   reg [3:0] phase;
+   reg [3:0] base_addr;
+
+   wire      signed [15:0] mac_out,middle_data, sum, coeff;
+   wire      signed [30:0] product;
+   wire      signed [33:0] sum_even;
+   wire      clear;
+   reg 	     store_odd;
+   
+   always @(posedge clock)
+     if(reset)
+       store_odd <= #1 1'b0;
+     else
+       if(strobe_in)
+	 store_odd <= #1 ~store_odd;
+
+   wire      start = strobe_in & store_odd;
+   always @(posedge clock)
+     if(reset)
+       base_addr <= #1 4'd0;
+     else if(start)
+       base_addr <= #1 base_addr + 4'd1;
+
+   always @(posedge clock)
+     if(reset)
+       phase <= #1 4'd8;
+     else if (start)
+       phase <= #1 4'd0;
+     else if(phase != 4'd8)
+       phase <= #1 phase + 4'd1;
+
+   reg 	     start_d1,start_d2,start_d3,start_d4,start_d5,start_d6,start_d7,start_d8,start_d9,start_dA,start_dB,start_dC,start_dD;
+   always @(posedge clock)
+     begin
+	start_d1 <= #1 start;
+	start_d2 <= #1 start_d1;
+	start_d3 <= #1 start_d2;
+	start_d4 <= #1 start_d3;
+	start_d5 <= #1 start_d4;
+	start_d6 <= #1 start_d5;
+	start_d7 <= #1 start_d6;
+	start_d8 <= #1 start_d7;
+	start_d9 <= #1 start_d8;
+	start_dA <= #1 start_d9;
+	start_dB <= #1 start_dA;
+	start_dC <= #1 start_dB;
+	start_dD <= #1 start_dC;
+     end // always @ (posedge clock)
+   
+   reg 	  mult_en, mult_en_pre;
+   always @(posedge clock)
+     begin
+	mult_en_pre <= #1 phase!=8;
+	mult_en <= #1 mult_en_pre;
+     end
+   
+   assign clear = start_d4; // was dC
+   wire   latch_result = start_d4; // was dC
+   assign strobe_out = start_d5; // was dD
+   wire   acc_en;
+   
+   always @*
+     case(phase[2:0])
+       3'd0 : begin rd_addr1 = base_addr + 4'd0; rd_addr2 = base_addr + 4'd15; end
+       3'd1 : begin rd_addr1 = base_addr + 4'd1; rd_addr2 = base_addr + 4'd14; end
+       3'd2 : begin rd_addr1 = base_addr + 4'd2; rd_addr2 = base_addr + 4'd13; end
+       3'd3 : begin rd_addr1 = base_addr + 4'd3; rd_addr2 = base_addr + 4'd12; end
+       3'd4 : begin rd_addr1 = base_addr + 4'd4; rd_addr2 = base_addr + 4'd11; end
+       3'd5 : begin rd_addr1 = base_addr + 4'd5; rd_addr2 = base_addr + 4'd10; end
+       3'd6 : begin rd_addr1 = base_addr + 4'd6; rd_addr2 = base_addr + 4'd9; end
+       3'd7 : begin rd_addr1 = base_addr + 4'd7; rd_addr2 = base_addr + 4'd8; end
+       default: begin rd_addr1 = base_addr + 4'd0; rd_addr2 = base_addr + 4'd15; end
+     endcase // case(phase)
+   
+   coeff_rom coeff_rom (.clock(clock),.addr(phase[2:0]-3'd1),.data(coeff));
+   
+   ram16_2sum ram16_even (.clock(clock),.write(strobe_in & ~store_odd),
+			  .wr_addr(base_addr),.wr_data(data_in),
+			  .rd_addr1(rd_addr1),.rd_addr2(rd_addr2),
+			  .sum(sum));
+
+   ram16 ram16_odd (.clock(clock),.write(strobe_in & store_odd),  // Holds middle items
+		    .wr_addr(base_addr),.wr_data(data_in),
+		    //.rd_addr(base_addr+4'd7),.rd_data(middle_data));
+		    .rd_addr(base_addr+4'd6),.rd_data(middle_data));
+
+   mult mult(.clock(clock),.x(coeff),.y(sum),.product(product),.enable_in(mult_en),.enable_out(acc_en));
+
+   acc acc(.clock(clock),.reset(reset),.enable_in(acc_en),.enable_out(),
+	   .clear(clear),.addend(product),.sum(sum_even));
+
+   wire signed [33:0] dout = sum_even + {{4{middle_data[15]}},middle_data,14'b0}; // We already divided product by 2!!!!
+
+   always @(posedge clock)
+     if(reset)
+       data_out <= #1 16'd0;
+     else if(latch_result)
+       data_out <= #1 dout[30:15] + (dout[33]& |dout[14:0]);
+
+   assign  debugctrl = { clock,reset,acc_en,mult_en,clear,latch_result,store_odd,strobe_in,strobe_out,phase};
+   
+endmodule // halfband_decim
diff --git a/usrp2/sdr_lib/hb/halfband_interp.v b/usrp2/sdr_lib/hb/halfband_interp.v
new file mode 100644
index 000000000..cdb11c1f6
--- /dev/null
+++ b/usrp2/sdr_lib/hb/halfband_interp.v
@@ -0,0 +1,121 @@
+
+
+module halfband_interp 
+  (input clock, input reset, input enable,
+   input strobe_in, input strobe_out,
+   input [15:0] signal_in_i, input [15:0] signal_in_q, 
+   output reg [15:0] signal_out_i, output reg [15:0] signal_out_q,
+   output wire [12:0] debug);
+   
+   wire [15:0] 	coeff_ram_out;
+   wire [15:0] 	data_ram_out_i;
+   wire [15:0] 	data_ram_out_q;
+
+   wire [3:0] 	data_rd_addr;
+   reg [3:0] 	data_wr_addr;
+   reg [2:0] 	coeff_rd_addr;
+
+   wire 		filt_done;
+   
+   wire [15:0] 	mac_out_i;
+   wire [15:0] 	mac_out_q;
+   reg [15:0] 	delayed_middle_i, delayed_middle_q;
+   wire [7:0] 	shift = 8'd9;
+
+   reg 		stb_out_happened;
+
+   wire [15:0] 	data_ram_out_i_b;
+   
+   always @(posedge clock)
+     if(strobe_in)
+       stb_out_happened <= #1 1'b0;
+     else if(strobe_out)
+       stb_out_happened <= #1 1'b1;
+   
+assign debug = {filt_done,data_rd_addr,data_wr_addr,coeff_rd_addr};
+
+   wire [15:0] 	signal_out_i = stb_out_happened ? mac_out_i : delayed_middle_i;
+   wire [15:0] 	signal_out_q = stb_out_happened ? mac_out_q : delayed_middle_q;
+
+/*   always @(posedge clock)
+     if(reset)
+       begin
+	  signal_out_i <= #1 16'd0;
+	  signal_out_q <= #1 16'd0;
+       end
+     else if(strobe_in)
+       begin
+	  signal_out_i <= #1 delayed_middle_i; // Multiply by 1 for middle coeff
+	  signal_out_q <= #1 delayed_middle_q;
+       end
+     //else if(filt_done&stb_out_happened)
+     else if(stb_out_happened)
+       begin
+	  signal_out_i <= #1 mac_out_i;
+	  signal_out_q <= #1 mac_out_q;
+       end
+*/
+   
+   always @(posedge clock)
+     if(reset)
+       coeff_rd_addr <= #1 3'd0;
+     else if(coeff_rd_addr != 3'd0)
+       coeff_rd_addr <= #1 coeff_rd_addr + 3'd1;
+     else if(strobe_in)
+       coeff_rd_addr <= #1 3'd1;
+
+   reg filt_done_d1;
+   always@(posedge clock)
+     filt_done_d1 <= #1 filt_done;
+   
+   always @(posedge clock)
+     if(reset)
+       data_wr_addr <= #1 4'd0;
+   //else if(strobe_in)
+     else if(filt_done & ~filt_done_d1)
+       data_wr_addr <= #1 data_wr_addr + 4'd1;
+
+   always @(posedge clock)
+     if(coeff_rd_addr == 3'd7)
+       begin
+	  delayed_middle_i <= #1 data_ram_out_i_b;
+	//  delayed_middle_q <= #1 data_ram_out_q_b;
+       end
+   
+//   always @(posedge clock)
+//     if(reset)
+//       data_rd_addr <= #1 4'd0;
+//     else if(strobe_in)
+//       data_rd_addr <= #1 data_wr_addr + 4'd1;
+//     else if(!filt_done)
+//       data_rd_addr <= #1 data_rd_addr + 4'd1;
+//     else
+//       data_rd_addr <= #1 data_wr_addr;
+  
+   wire [3:0] data_rd_addr1 = data_wr_addr + {1'b0,coeff_rd_addr};
+   wire [3:0] data_rd_addr2 = data_wr_addr + 15 - {1'b0,coeff_rd_addr};
+//   always @(posedge clock)
+//     if(reset)
+//       filt_done <= #1 1'b1;
+//     else if(strobe_in)
+ //      filt_done <= #1 1'b0;
+//     else if(coeff_rd_addr == 4'd0)
+//       filt_done <= #1 1'b1;
+
+   assign filt_done = (coeff_rd_addr == 3'd0);
+   
+   coeff_ram coeff_ram ( .clock(clock),.rd_addr({1'b0,coeff_rd_addr}),.rd_data(coeff_ram_out) );
+   
+   ram16_2sum data_ram_i ( .clock(clock),.write(strobe_in),.wr_addr(data_wr_addr),.wr_data(signal_in_i),
+		      .rd_addr1(data_rd_addr1),.rd_addr2(data_rd_addr2),.rd_data(data_ram_out_i_b),.sum(data_ram_out_i));
+   
+   ram16_2sum data_ram_q ( .clock(clock),.write(strobe_in),.wr_addr(data_wr_addr),.wr_data(signal_in_q),
+		      .rd_addr1(data_rd_addr1),.rd_addr2(data_rd_addr2),.rd_data(data_ram_out_q));
+   
+   mac mac_i (.clock(clock),.reset(reset),.enable(~filt_done),.clear(strobe_in),
+	      .x(data_ram_out_i),.y(coeff_ram_out),.shift(shift),.z(mac_out_i) );
+   
+   mac mac_q (.clock(clock),.reset(reset),.enable(~filt_done),.clear(strobe_in),
+	      .x(data_ram_out_q),.y(coeff_ram_out),.shift(shift),.z(mac_out_q) );
+
+endmodule // halfband_interp
diff --git a/usrp2/sdr_lib/hb/hbd_tb/HBD b/usrp2/sdr_lib/hb/hbd_tb/HBD
new file mode 100644
index 000000000..574fbba91
--- /dev/null
+++ b/usrp2/sdr_lib/hb/hbd_tb/HBD
@@ -0,0 +1,80 @@
+*-6.432683 5736 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1
+@28
+test_hbd.clock
+test_hbd.reset
+@420
+test_hbd.halfband_decim.middle_data[15:0]
+@22
+test_hbd.halfband_decim.sum_even[33:0]
+test_hbd.halfband_decim.base_addr[3:0]
+@420
+test_hbd.i_in[15:0]
+@24
+test_hbd.halfband_decim.phase[3:0]
+test_hbd.halfband_decim.ram16_even.rd_addr1[3:0]
+test_hbd.halfband_decim.ram16_even.rd_addr2[3:0]
+test_hbd.halfband_decim.ram16_even.wr_addr[3:0]
+test_hbd.halfband_decim.ram16_even.wr_data[15:0]
+@28
+test_hbd.halfband_decim.ram16_even.write
+@420
+test_hbd.halfband_decim.sum[15:0]
+test_hbd.halfband_decim.product[30:0]
+test_hbd.halfband_decim.dout[33:0]
+test_hbd.halfband_decim.sum_even[33:0]
+@22
+test_hbd.halfband_decim.acc.addend[30:0]
+@28
+test_hbd.halfband_decim.acc.reset
+@420
+test_hbd.halfband_decim.acc.sum[33:0]
+test_hbd.halfband_decim.mult.x[15:0]
+test_hbd.halfband_decim.mult.y[15:0]
+@28
+test_hbd.halfband_decim.acc.clear
+test_hbd.strobe_in
+test_hbd.strobe_out
+test_hbd.halfband_decim.acc_en
+@420
+test_hbd.i_out[15:0]
+@28
+test_hbd.halfband_decim.mult_en
+test_hbd.halfband_decim.latch_result
+@420
+test_hbd.halfband_decim.sum[15:0]
+test_hbd.halfband_decim.sum_even[33:0]
+test_hbd.halfband_decim.dout[33:0]
+test_hbd.halfband_decim.data_out[15:0]
+@22
+test_hbd.halfband_decim.data_out[15:0]
+@28
+test_hbd.halfband_decim.dout[33:0]
+@29
+test_hbd.halfband_decim.acc_en
+@22
+test_hbd.halfband_decim.base_addr[3:0]
+@28
+test_hbd.halfband_decim.clear
+test_hbd.halfband_decim.latch_result
+test_hbd.halfband_decim.mult_en
+test_hbd.halfband_decim.mult_en_pre
+@22
+test_hbd.halfband_decim.phase[3:0]
+@28
+test_hbd.halfband_decim.start
+test_hbd.halfband_decim.start_d1
+test_hbd.halfband_decim.start_d2
+test_hbd.halfband_decim.start_d3
+test_hbd.halfband_decim.start_d4
+test_hbd.halfband_decim.start_d5
+test_hbd.halfband_decim.start_d6
+test_hbd.halfband_decim.start_d7
+test_hbd.halfband_decim.start_d8
+test_hbd.halfband_decim.start_d9
+test_hbd.halfband_decim.start_dA
+test_hbd.halfband_decim.start_dB
+test_hbd.halfband_decim.start_dC
+test_hbd.halfband_decim.start_dD
+test_hbd.halfband_decim.store_odd
+test_hbd.halfband_decim.strobe_in
+test_hbd.halfband_decim.strobe_out
diff --git a/usrp2/sdr_lib/hb/hbd_tb/really_golden b/usrp2/sdr_lib/hb/hbd_tb/really_golden
new file mode 100644
index 000000000..2d24a9e14
--- /dev/null
+++ b/usrp2/sdr_lib/hb/hbd_tb/really_golden
@@ -0,0 +1,142 @@
+VCD info: dumpfile test_hbd.vcd opened for output.
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    x
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+ 8192
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+    0
+-     4
+   18
+-    63
+  167
+-   367
+  737
+-  1539
+ 5146
+ 5146
+-  1539
+  737
+-   367
+  167
+-    63
+   18
+-     4
+    0
+    0
+    0
+    0
+    0
+-     4
+   14
+-    49
+  118
+-   249
+  488
+ 7141
+12287
+17433
+15894
+16631
+16264
+16432
+16368
+16387
+16383
+16383
+16383
+16383
+16383
+16387
+16368
+16432
+16264
+16631
+15894
+ 9241
+ 4095
+-  1051
+  488
+-   249
+  118
+-    49
+   14
+-     4
+    0
+    0
+    0
+    0
+    0
+-     4
+   14
+-    49
+  118
+-   249
+  488
+-  1051
+12287
+17433
+15894
+16631
+16264
+16432
+16368
+16387
+16383
+16383
+16383
+16383
+16383
+16387
+16368
+16432
+16264
+16631
+15894
+17433
+ 4095
+-  1051
+  488
+-   249
+  118
+-    49
+   14
+-     4
+    0
+    0
+    0
+    0
diff --git a/usrp2/sdr_lib/hb/hbd_tb/regression b/usrp2/sdr_lib/hb/hbd_tb/regression
new file mode 100644
index 000000000..fc279c2f2
--- /dev/null
+++ b/usrp2/sdr_lib/hb/hbd_tb/regression
@@ -0,0 +1,95 @@
+echo "Baseline 1000"
+iverilog -y .. -o test_hbd -DRATE=1000 test_hbd.v  ; ./test_hbd >golden
+diff golden really_golden
+
+echo
+echo "Test 100"
+iverilog -y .. -o test_hbd -DRATE=100 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 50"
+iverilog -y .. -o test_hbd -DRATE=50 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 40"
+iverilog -y .. -o test_hbd -DRATE=40 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 30"
+iverilog -y .. -o test_hbd -DRATE=30 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 25"
+iverilog -y .. -o test_hbd -DRATE=25 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 20"
+iverilog -y .. -o test_hbd -DRATE=20 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 19"
+iverilog -y .. -o test_hbd -DRATE=19 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 18"
+iverilog -y .. -o test_hbd -DRATE=18 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 17"
+iverilog -y .. -o test_hbd -DRATE=17 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 16"
+iverilog -y .. -o test_hbd -DRATE=16 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 15"
+iverilog -y .. -o test_hbd -DRATE=15 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 14"
+iverilog -y .. -o test_hbd -DRATE=14 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 13"
+iverilog -y .. -o test_hbd -DRATE=13 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 12"
+iverilog -y .. -o test_hbd -DRATE=12 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 11"
+iverilog -y .. -o test_hbd -DRATE=11 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 10"
+iverilog -y .. -o test_hbd -DRATE=10 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 9"
+iverilog -y .. -o test_hbd -DRATE=9 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 8"
+iverilog -y .. -o test_hbd -DRATE=8 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 7"
+iverilog -y .. -o test_hbd -DRATE=7 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 6"
+iverilog -y .. -o test_hbd -DRATE=6 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 5"
+iverilog -y .. -o test_hbd -DRATE=5 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 4"
+iverilog -y .. -o test_hbd -DRATE=4 test_hbd.v  ; ./test_hbd >output ; diff output golden
+
+echo
+echo "Test 3"
+iverilog -y .. -o test_hbd -DRATE=3 test_hbd.v  ; ./test_hbd >output ; diff output golden
diff --git a/usrp2/sdr_lib/hb/hbd_tb/run_hbd b/usrp2/sdr_lib/hb/hbd_tb/run_hbd
new file mode 100755
index 000000000..b8aec7574
--- /dev/null
+++ b/usrp2/sdr_lib/hb/hbd_tb/run_hbd
@@ -0,0 +1,4 @@
+#!/bin/sh
+
+iverilog -y .. -o test_hbd test_hbd.v
+./test_hbd
diff --git a/usrp2/sdr_lib/hb/hbd_tb/test_hbd.v b/usrp2/sdr_lib/hb/hbd_tb/test_hbd.v
new file mode 100644
index 000000000..01ab5e7e0
--- /dev/null
+++ b/usrp2/sdr_lib/hb/hbd_tb/test_hbd.v
@@ -0,0 +1,75 @@
+
+
+module test_hbd();
+
+   reg clock;
+   initial clock = 1'b0;
+   always #5 clock <= ~clock;
+
+   reg reset;
+   initial reset = 1'b1;
+   initial #1000 reset = 1'b0;
+   
+   initial $dumpfile("test_hbd.vcd");
+   initial $dumpvars(0,test_hbd);
+
+   reg [15:0] i_in, q_in;
+   wire [15:0] i_out, q_out;
+
+   reg 	       strobe_in;
+   wire        strobe_out;
+   reg 	       coeff_write;
+   reg [15:0]  coeff_data;
+   reg [4:0]   coeff_addr;
+   
+   halfband_decim halfband_decim 
+     ( .clock(clock),.reset(reset),.enable(),.strobe_in(strobe_in),.strobe_out(strobe_out),
+       .data_in(i_in),.data_out(i_out) );
+   
+   always @(posedge strobe_out)
+     if(i_out[15])
+       $display("-%d",65536-i_out);
+     else
+       $display("%d",i_out);
+
+   initial
+     begin
+	strobe_in = 1'b0;
+	@(negedge reset);
+	@(posedge clock);
+	while(1)
+	  begin
+	     strobe_in <= #1 1'b1;
+	     @(posedge clock);
+	     strobe_in <= #1 1'b0;
+	     repeat (`RATE)
+	       @(posedge clock);
+	  end
+     end
+
+   initial #10000000 $finish;    // Just in case...
+
+   initial
+     begin
+	i_in <= #1 16'd0;
+	repeat (40) @(posedge strobe_in);
+	i_in <= #1 16'd16384;
+	@(posedge strobe_in);
+	i_in <= #1 16'd0;
+	repeat (40) @(posedge strobe_in);
+	i_in <= #1 16'd16384;
+	@(posedge strobe_in);
+	i_in <= #1 16'd0;
+	repeat (40) @(posedge strobe_in);
+	i_in <= #1 16'd16384;
+	repeat (40) @(posedge strobe_in);
+	i_in <= #1 16'd0;
+	repeat (41) @(posedge strobe_in);
+	i_in <= #1 16'd16384;
+	repeat (40) @(posedge strobe_in);
+	i_in <= #1 16'd0;
+	repeat (40) @(posedge strobe_in);
+	repeat (7) @(posedge clock);
+	$finish;
+     end // initial begin
+endmodule // test_hb
diff --git a/usrp2/sdr_lib/hb/mac.v b/usrp2/sdr_lib/hb/mac.v
new file mode 100644
index 000000000..5a270bc73
--- /dev/null
+++ b/usrp2/sdr_lib/hb/mac.v
@@ -0,0 +1,58 @@
+
+
+module mac (input clock, input reset, input enable, input clear,
+	    input signed [15:0] x, input signed [15:0] y,
+	    input [7:0] shift, output [15:0] z );
+
+   reg signed [30:0] product;
+   reg signed [39:0] z_int;
+   reg signed [15:0] z_shift;
+
+   reg enable_d1;
+   always @(posedge clock)
+     enable_d1 <= #1 enable;
+   
+   always @(posedge clock)
+     if(reset | clear)
+       z_int <= #1 40'd0;
+     else if(enable_d1)
+       z_int <= #1 z_int + {{9{product[30]}},product};
+
+   always @(posedge clock)
+     product <= #1 x*y;
+
+   always @*   // FIXME full case? parallel case?
+     case(shift)
+       //8'd0 : z_shift <= z_int[39:24];
+       //8'd1 : z_shift <= z_int[38:23];
+       //8'd2 : z_shift <= z_int[37:22];
+       //8'd3 : z_shift <= z_int[36:21];
+       //8'd4 : z_shift <= z_int[35:20];
+       //8'd5 : z_shift <= z_int[34:19];
+       8'd6 : z_shift <= z_int[33:18];
+       8'd7 : z_shift <= z_int[32:17];
+       8'd8 : z_shift <= z_int[31:16];
+       8'd9 : z_shift <= z_int[30:15];
+       8'd10 : z_shift <= z_int[29:14];
+       8'd11 : z_shift <= z_int[28:13];
+       //8'd12 : z_shift <= z_int[27:12];
+       //8'd13 : z_shift <= z_int[26:11];
+       //8'd14 : z_shift <= z_int[25:10];
+       //8'd15 : z_shift <= z_int[24:9];
+       //8'd16 : z_shift <= z_int[23:8];
+       //8'd17 : z_shift <= z_int[22:7];
+       //8'd18 : z_shift <= z_int[21:6];
+       //8'd19 : z_shift <= z_int[20:5];
+       //8'd20 : z_shift <= z_int[19:4];
+       //8'd21 : z_shift <= z_int[18:3];
+       //8'd22 : z_shift <= z_int[17:2];
+       //8'd23 : z_shift <= z_int[16:1];
+       //8'd24 : z_shift <= z_int[15:0];
+       default : z_shift <= z_int[15:0];
+     endcase // case(shift)
+   
+   // FIXME do we need to saturate?
+   //assign z = z_shift;
+   assign z = z_int[15:0];
+   
+endmodule // mac
diff --git a/usrp2/sdr_lib/hb/mult.v b/usrp2/sdr_lib/hb/mult.v
new file mode 100644
index 000000000..a8d4cb1b7
--- /dev/null
+++ b/usrp2/sdr_lib/hb/mult.v
@@ -0,0 +1,16 @@
+
+
+module mult (input clock, input signed [15:0] x, input signed [15:0] y, output reg signed [30:0] product,
+	     input enable_in, output reg enable_out );
+
+   always @(posedge clock)
+     if(enable_in)
+       product <= #1 x*y;
+     else
+       product <= #1 31'd0;
+   
+   always @(posedge clock)
+     enable_out <= #1 enable_in;
+   
+endmodule // mult
+
diff --git a/usrp2/sdr_lib/hb/ram16_2port.v b/usrp2/sdr_lib/hb/ram16_2port.v
new file mode 100644
index 000000000..e1761a926
--- /dev/null
+++ b/usrp2/sdr_lib/hb/ram16_2port.v
@@ -0,0 +1,22 @@
+
+
+module ram16_2port (input clock, input write, 
+		    input [3:0] wr_addr, input [15:0] wr_data,
+		    input [3:0] rd_addr1, output reg [15:0] rd_data1,
+		    input [3:0] rd_addr2, output reg [15:0] rd_data2);
+   
+   reg [15:0] 			ram_array [0:31];
+   
+   always @(posedge clock)
+     rd_data1 <= #1 ram_array[rd_addr1];
+   
+   always @(posedge clock)
+     rd_data2 <= #1 ram_array[rd_addr2];
+   
+   always @(posedge clock)
+     if(write)
+       ram_array[wr_addr] <= #1 wr_data;
+   
+endmodule // ram16_2port
+
+
diff --git a/usrp2/sdr_lib/hb/ram16_2sum.v b/usrp2/sdr_lib/hb/ram16_2sum.v
new file mode 100644
index 000000000..559b06fd5
--- /dev/null
+++ b/usrp2/sdr_lib/hb/ram16_2sum.v
@@ -0,0 +1,27 @@
+
+
+module ram16_2sum (input clock, input write, 
+		   input [3:0] wr_addr, input [15:0] wr_data,
+		   input [3:0] rd_addr1, input [3:0] rd_addr2,
+                   output reg [15:0] sum);
+   
+   reg signed [15:0] 	  ram_array [0:15];
+   reg signed [15:0] 	  a,b;
+   wire signed [16:0] 	  sum_int;
+   
+   always @(posedge clock)
+     if(write)
+       ram_array[wr_addr] <= #1 wr_data;
+      
+   always @(posedge clock)
+     begin
+	a <= #1 ram_array[rd_addr1];
+	b <= #1 ram_array[rd_addr2];
+     end
+   
+   assign sum_int = {a[15],a} + {b[15],b};
+   
+   always @(posedge clock)
+     sum <= #1 sum_int[16:1] + (sum_int[16]&sum_int[0]);
+     
+endmodule // ram16_2sum
diff --git a/usrp2/sdr_lib/hb/ram32_2sum.v b/usrp2/sdr_lib/hb/ram32_2sum.v
new file mode 100644
index 000000000..d1f55b7d0
--- /dev/null
+++ b/usrp2/sdr_lib/hb/ram32_2sum.v
@@ -0,0 +1,22 @@
+
+
+module ram32_2sum (input clock, input write, 
+		   input [4:0] wr_addr, input [15:0] wr_data,
+		   input [4:0] rd_addr1, input [4:0] rd_addr2,
+		   output reg [15:0] sum);
+   
+   reg [15:0] 			ram_array [0:31];
+   wire [16:0] 			sum_int;
+   
+   always @(posedge clock)
+     if(write)
+       ram_array[wr_addr] <= #1 wr_data;
+
+   assign sum_int = ram_array[rd_addr1] + ram_array[rd_addr2];
+
+   always @(posedge clock)
+     sum <= #1 sum_int[16:1] + (sum_int[16]&sum_int[0]);
+
+   
+endmodule // ram32_2sum
+
diff --git a/usrp2/sdr_lib/hb_dec.v b/usrp2/sdr_lib/hb_dec.v
new file mode 100644
index 000000000..8fb5ba222
--- /dev/null
+++ b/usrp2/sdr_lib/hb_dec.v
@@ -0,0 +1,171 @@
+// Final halfband decimator 
+// Implements impulse responses of the form [A 0 B 0 C .. 0 H 0.5 H 0 .. C 0 B 0 A]
+// Strobe in cannot come faster than every 2nd clock cycle
+// These taps designed by halfgen4 from ldoolittle
+// myfilt = round(2^18 * halfgen4(.7/4,8))
+
+module hb_dec
+  #(parameter IWIDTH=18, OWIDTH=18, CWIDTH=18, ACCWIDTH=24)
+    (input clk,
+     input rst,
+     input bypass,
+     input run,
+     input [8:0] cpi,  // Clocks per input -- equal to the decimation ratio ahead of this block
+     input stb_in,
+     input [IWIDTH-1:0] data_in,
+     output reg stb_out,
+     output reg [OWIDTH-1:0] data_out);
+
+   // Control
+   reg [3:0] 		addr_odd_a, addr_odd_b, addr_odd_c, addr_odd_d;
+   wire 		write_odd, write_even, do_mult;
+   reg 			odd;
+   reg [2:0] 		phase, phase_d1;
+   reg 			stb_out_int;
+   wire 		clear, do_acc;
+   assign 		do_mult = 1;
+   
+   always @(posedge clk)
+     if(rst | ~run)
+       odd <= 0;
+     else if(stb_in)
+       odd <= ~odd;
+
+   assign 		write_odd = stb_in & odd;
+   assign 		write_even = stb_in & ~odd;
+
+   always @(posedge clk)
+     if(rst | ~run)
+       phase <= 0;
+     else if(stb_in & odd)
+       phase <= 1;
+     else if(phase == 4)
+       phase <= 0;
+     else if(phase != 0)
+       phase <= phase + 1;
+
+   always @(posedge clk)
+     phase_d1 <= phase;
+   
+   reg [15:0] 		stb_out_pre;
+   always @(posedge clk)
+     if(rst)
+       stb_out_pre <= 0;
+     else
+       stb_out_pre <= {stb_out_pre[14:0],(stb_in & odd)};
+
+   always @*
+     case(phase)
+       1 : begin addr_odd_a = 0; addr_odd_b = 15; end
+       2 : begin addr_odd_a = 1; addr_odd_b = 14; end
+       3 : begin addr_odd_a = 2; addr_odd_b = 13; end
+       4 : begin addr_odd_a = 3; addr_odd_b = 12; end
+       default : begin addr_odd_a = 0; addr_odd_b = 15; end
+     endcase // case(phase)
+
+   always @*
+     case(phase)
+       1 : begin addr_odd_c = 4; addr_odd_d = 11; end
+       2 : begin addr_odd_c = 5; addr_odd_d = 10; end
+       3 : begin addr_odd_c = 6; addr_odd_d = 9; end
+       4 : begin addr_odd_c = 7; addr_odd_d = 8; end
+       default : begin addr_odd_c = 4; addr_odd_d = 11; end
+     endcase // case(phase)
+
+   assign do_acc = |stb_out_pre[6:3];
+   assign clear = stb_out_pre[3];
+   
+   // Data
+   wire [IWIDTH-1:0] data_odd_a, data_odd_b, data_odd_c, data_odd_d;
+   wire [IWIDTH-1:0] sum1, sum2;	
+   wire [OWIDTH-1:0] final_sum;
+   reg [CWIDTH-1:0]  coeff1, coeff2;
+   wire [35:0] 	     prod1, prod2;
+
+   always @*            // Outer coeffs
+     case(phase_d1)
+       1 : coeff1 = -107;
+       2 : coeff1 = 445;
+       3 : coeff1 = -1271;
+       4 : coeff1 = 2959;
+       default : coeff1 = -107;
+     endcase // case(phase)
+   
+   always @*            //  Inner coeffs
+     case(phase_d1)
+       1 : coeff2 = -6107;
+       2 : coeff2 = 11953;
+       3 : coeff2 = -24706;
+       4 : coeff2 = 82359;
+       default : coeff2 = -6107;
+     endcase // case(phase)
+   
+   srl #(.WIDTH(IWIDTH)) srl_odd_a
+     (.clk(clk),.write(write_odd),.in(data_in),.addr(addr_odd_a),.out(data_odd_a));
+   srl #(.WIDTH(IWIDTH)) srl_odd_b
+     (.clk(clk),.write(write_odd),.in(data_in),.addr(addr_odd_b),.out(data_odd_b));
+   srl #(.WIDTH(IWIDTH)) srl_odd_c
+     (.clk(clk),.write(write_odd),.in(data_in),.addr(addr_odd_c),.out(data_odd_c));
+   srl #(.WIDTH(IWIDTH)) srl_odd_d
+     (.clk(clk),.write(write_odd),.in(data_in),.addr(addr_odd_d),.out(data_odd_d));
+
+   add2_reg /*_and_round_reg*/ #(.WIDTH(IWIDTH)) add1 (.clk(clk),.in1(data_odd_a),.in2(data_odd_b),.sum(sum1));
+   add2_reg /*_and_round_reg*/ #(.WIDTH(IWIDTH)) add2 (.clk(clk),.in1(data_odd_c),.in2(data_odd_d),.sum(sum2));
+
+   wire [IWIDTH-1:0] data_even;
+   reg [3:0] 	     addr_even;
+
+   always @(posedge clk)
+     case(cpi)
+       //  1 is an error
+       2 : addr_even <= 9;  // Maximum speed (overall decim by 4)
+       3, 4, 5, 6, 7 : addr_even <= 8;
+       default : addr_even <= 7;
+     endcase // case(cpi)
+   
+   srl #(.WIDTH(IWIDTH)) srl_even
+     (.clk(clk),.write(write_even),.in(data_in),.addr(addr_even),.out(data_even));
+
+   localparam 		MWIDTH = ACCWIDTH-2;   
+   wire [MWIDTH-1:0] 	sum_of_prod;
+
+   MULT18X18S mult1(.C(clk), .CE(do_mult), .R(rst), .P(prod1), .A(coeff1), .B(sum1) );
+   MULT18X18S mult2(.C(clk), .CE(do_mult), .R(rst), .P(prod2), .A(coeff2), .B(sum2) );
+   add2_and_round_reg #(.WIDTH(MWIDTH)) 
+     add3 (.clk(clk),.in1(prod1[35:36-MWIDTH]),.in2(prod2[35:36-MWIDTH]),.sum(sum_of_prod));
+
+   wire [ACCWIDTH-1:0] 	acc_out;
+   
+   acc #(.IWIDTH(MWIDTH),.OWIDTH(ACCWIDTH)) 
+     acc (.clk(clk),.clear(clear),.acc(do_acc),.in(sum_of_prod),.out(acc_out));
+
+   localparam 		SHIFT_FACTOR = ACCWIDTH-IWIDTH-5;
+   wire [ACCWIDTH-1:0] 	data_even_signext;
+   wire [ACCWIDTH:0] 	final_sum_unrounded;
+
+   sign_extend #(.bits_in(IWIDTH),.bits_out(ACCWIDTH-SHIFT_FACTOR))
+     signext_data_even (.in(data_even),.out(data_even_signext[ACCWIDTH-1:SHIFT_FACTOR]));
+   assign 		data_even_signext[SHIFT_FACTOR-1:0] = 0;
+   
+   add2_reg /* add2_and_round_reg */ #(.WIDTH(ACCWIDTH+1)) 
+     final_adder (.clk(clk), .in1({acc_out,1'b0}), .in2({data_even_signext,1'b0}), .sum(final_sum_unrounded));
+
+   round_reg #(.bits_in(ACCWIDTH-4),.bits_out(OWIDTH))
+     final_round (.clk(clk),.in(final_sum_unrounded[ACCWIDTH-5:0]),.out(final_sum));
+
+   // Output
+   always @(posedge clk)
+     if(bypass)
+       data_out <= data_in;
+     else if(stb_out_pre[9])
+       data_out <= final_sum;
+
+   always @(posedge clk)
+     if(rst)
+       stb_out <= 0;
+     else if(bypass)
+       stb_out <= stb_in;
+     else
+       stb_out <= stb_out_pre[9];
+ 
+endmodule // hb_dec
diff --git a/usrp2/sdr_lib/hb_dec_tb.v b/usrp2/sdr_lib/hb_dec_tb.v
new file mode 100644
index 000000000..3e5faa80a
--- /dev/null
+++ b/usrp2/sdr_lib/hb_dec_tb.v
@@ -0,0 +1,140 @@
+module hb_dec_tb( ) ;
+   
+    // Parameters for instantiation
+    parameter               clocks  = 9'd2 ; // Number of clocks per input
+    parameter               decim   = 1 ; // Sets the filter to decimate
+    parameter               rate    = 2 ; // Sets the decimation rate
+
+    reg                     clock ;
+    reg                     reset ;
+    reg                     enable ;
+    reg                     strobe_in ;
+    reg     signed  [17:0]  data_in ;
+    wire                    strobe_out ;
+    wire    signed  [17:0]  data_out ;
+
+   initial
+     begin
+	$dumpfile("hb_dec_tb.vcd");
+	$dumpvars(0,hb_dec_tb);
+     end
+   
+    // Setup the clock
+    initial clock = 1'b0 ;
+    always #5 clock <= ~clock ;
+
+    // Come out of reset after a while
+    initial reset = 1'b1 ;
+    initial #1000 reset = 1'b0 ;
+
+    // Enable the entire system
+    initial enable = 1'b1 ;
+
+    // Instantiate UUT
+   /*
+    halfband_ideal 
+      #(
+        .decim      ( decim         ),
+        .rate       ( rate          )
+      ) uut(
+        .clock      ( clock         ),
+        .reset      ( reset         ),
+        .enable     ( enable        ),
+        .strobe_in  ( strobe_in     ),
+        .data_in    ( data_in       ),
+        .strobe_out ( strobe_out    ),
+        .data_out   ( data_out      )
+      ) ;
+    */
+
+   
+   hb_dec #(.IWIDTH(18),.OWIDTH(18),.CWIDTH(18),.ACCWIDTH(24)) uut
+     (.clk(clock),.rst(reset),.bypass(0),.cpi(clocks),.stb_in(strobe_in),.data_in(data_in),
+      .stb_out(strobe_out),.data_out(data_out) );
+   
+    integer i, ri, ro, infile, outfile ;
+
+   always @(posedge clock)
+     begin
+	if(strobe_out)
+	  $display(data_out);
+     end
+   
+    // Setup file IO
+    initial begin
+        infile = $fopen("input.dat","r") ;
+        outfile = $fopen("output.dat","r") ;
+        $timeformat(-9, 2, " ns", 10) ;
+    end
+
+    reg                 endofsim ;
+    reg signed  [17:0]  compare ;
+    integer             noe ;
+    initial             noe = 0 ;
+
+    initial begin
+        // Initialize inputs
+        strobe_in <= 1'd0 ;
+        data_in <= 18'd0 ;
+
+        // Wait for reset to go away
+        @(negedge reset) #0 ;
+        
+        // While we're still simulating ...
+        while( !endofsim ) begin
+
+            // Write the input from the file or 0 if EOF...
+            @( posedge clock ) begin
+               //#1 ;
+                strobe_in <= 1'b1 ;
+                if( !$feof(infile) )
+                    ri = $fscanf( infile, "%d", data_in ) ;
+                else
+                    data_in <= 18'd0 ;
+            end
+
+            // Clocked in - set the strobe to 0 if the number of
+            // clocks per sample is greater than 1
+            if( clocks > 1 ) begin
+                @(posedge clock) begin
+                    strobe_in <= 1'b0  ;
+                end
+
+                // Wait for the specified number of cycles
+                for( i = 0 ; i < (clocks-2) ; i = i + 1 ) begin
+                    @(posedge clock) #1 ;
+                end
+            end
+        end
+
+        // Print out the number of errors that occured
+        if( noe )
+            $display( "FAILED: %d errors during simulation", noe ) ;
+        else
+            $display( "PASSED: Simulation successful" ) ;
+
+        $finish ;
+    end
+
+   // Output comparison of simulated values versus known good values
+   always @ (posedge clock) begin
+      if( reset )
+        endofsim <= 1'b0 ;
+      else begin
+         if( !$feof(outfile) ) begin
+            if( strobe_out ) begin
+               ro = $fscanf( outfile, "%d\n", compare ) ;
+               if( compare != data_out ) begin
+                  //$display( "%t: %d != %d", $realtime, data_out, compare ) ;
+                  noe = noe + 1 ;
+               end
+            end
+         end else begin
+            // Signal end of simulation when no more outputs
+            endofsim <= 1'b1 ;
+         end
+      end
+   end     
+
+endmodule // hb_dec_tb
+
diff --git a/usrp2/sdr_lib/hb_interp.v b/usrp2/sdr_lib/hb_interp.v
new file mode 100644
index 000000000..d16807e15
--- /dev/null
+++ b/usrp2/sdr_lib/hb_interp.v
@@ -0,0 +1,157 @@
+// First halfband iterpolator 
+// Implements impulse responses of the form [A 0 B 0 C .. 0 H 0.5 H 0 .. C 0 B 0 A]
+// Strobe in cannot come faster than every 4th clock cycle, 
+// Strobe out cannot come faster than every 2nd clock cycle
+
+// These taps designed by halfgen4 from ldoolittle
+// myfilt = round(2^18 * halfgen4(.7/4,8))
+
+module hb_interp
+  #(parameter IWIDTH=18, OWIDTH=18, ACCWIDTH=24)
+    (input clk,
+     input rst,
+     input bypass,
+     input [7:0] cpo, //  Clocks per output, must be at least 2
+     input stb_in,
+     input [IWIDTH-1:0] data_in,
+     input stb_out,
+     output reg [OWIDTH-1:0] data_out);
+
+   localparam MWIDTH = ACCWIDTH-2;
+   localparam CWIDTH = 18;
+
+   reg [CWIDTH-1:0] coeff1, coeff2;
+   reg [3:0] 	    addr_a, addr_b, addr_c, addr_d, addr_e;
+   wire [IWIDTH-1:0] data_a, data_b, data_c, data_d, data_e, sum1, sum2;
+   wire [35:0] 	     prod1, prod2;
+
+   reg [2:0] 	     phase, phase_d1, phase_d2, phase_d3, phase_d4, phase_d5;
+
+   always @(posedge clk)
+     if(rst)
+       phase <= 0;
+     else
+       if(stb_in)
+	 phase <= 1;
+       else if(phase==4)
+	 phase <= 0;
+       else if(phase!=0)
+	 phase <= phase + 1;
+   always @(posedge clk) phase_d1 <= phase;
+   always @(posedge clk) phase_d2 <= phase_d1;
+   always @(posedge clk) phase_d3 <= phase_d2;
+   always @(posedge clk) phase_d4 <= phase_d3;
+   always @(posedge clk) phase_d5 <= phase_d4;     
+   
+   srl #(.WIDTH(IWIDTH)) srl_a
+     (.clk(clk),.write(stb_in),.in(data_in),.addr(addr_a),.out(data_a));
+   srl #(.WIDTH(IWIDTH)) srl_b
+     (.clk(clk),.write(stb_in),.in(data_in),.addr(addr_b),.out(data_b));
+   srl #(.WIDTH(IWIDTH)) srl_c
+     (.clk(clk),.write(stb_in),.in(data_in),.addr(addr_c),.out(data_c));
+   srl #(.WIDTH(IWIDTH)) srl_d
+     (.clk(clk),.write(stb_in),.in(data_in),.addr(addr_d),.out(data_d));
+   srl #(.WIDTH(IWIDTH)) srl_e
+     (.clk(clk),.write(stb_in),.in(data_in),.addr(addr_e),.out(data_e));
+
+   always @*
+     case(phase)
+       1 : begin addr_a = 0; addr_b = 15; end
+       2 : begin addr_a = 1; addr_b = 14; end
+       3 : begin addr_a = 2; addr_b = 13; end
+       4 : begin addr_a = 3; addr_b = 12; end
+       default : begin addr_a = 0; addr_b = 15; end
+     endcase // case(phase)
+
+   always @*
+     case(phase)
+       1 : begin addr_c = 4; addr_d = 11; end
+       2 : begin addr_c = 5; addr_d = 10; end
+       3 : begin addr_c = 6; addr_d = 9; end
+       4 : begin addr_c = 7; addr_d = 8; end
+       default : begin addr_c = 4; addr_d = 11; end
+     endcase // case(phase)
+
+   always @*
+     case(cpo)
+       2 : addr_e <= 9;
+       3,4,5,6,7,8 : addr_e <= 8;
+       default : addr_e <= 7;  // This case works for 256, which = 0 due to overflow outside this block
+     endcase // case(cpo)
+   
+   always @*            // Outer coeffs
+     case(phase_d1)
+       1 : coeff1 = -107;
+       2 : coeff1 = 445;
+       3 : coeff1 = -1271;
+       4 : coeff1 = 2959;
+       default : coeff1 = -107;
+     endcase // case(phase)
+   
+   always @*            //  Inner coeffs
+     case(phase_d1)
+       1 : coeff2 = -6107;
+       2 : coeff2 = 11953;
+       3 : coeff2 = -24706;
+       4 : coeff2 = 82359;
+       default : coeff2 = -6107;
+     endcase // case(phase)
+
+   add2_reg /*_and_round_reg*/ #(.WIDTH(IWIDTH)) add1 (.clk(clk),.in1(data_a),.in2(data_b),.sum(sum1));
+   add2_reg /*_and_round_reg*/ #(.WIDTH(IWIDTH)) add2 (.clk(clk),.in1(data_c),.in2(data_d),.sum(sum2));
+   // sum1, sum2 available on phase_d1
+
+   wire do_mult = 1;
+   MULT18X18S mult1(.C(clk), .CE(do_mult), .R(rst), .P(prod1), .A(coeff1), .B(sum1) );
+   MULT18X18S mult2(.C(clk), .CE(do_mult), .R(rst), .P(prod2), .A(coeff2), .B(sum2) );
+   // prod1, prod2 available on phase_d2
+   
+   wire [MWIDTH-1:0] sum_of_prod;
+   
+   add2_and_round_reg #(.WIDTH(MWIDTH)) 
+     add3 (.clk(clk),.in1(prod1[35:36-MWIDTH]),.in2(prod2[35:36-MWIDTH]),.sum(sum_of_prod));
+   // sum_of_prod available on phase_d3
+   
+   wire [ACCWIDTH-1:0] acc_out;
+   wire [OWIDTH-1:0]   acc_round;
+
+   wire 	       clear = (phase_d3 == 1);
+   wire 	       do_acc = (phase_d3 != 0);
+   
+   acc #(.IWIDTH(MWIDTH),.OWIDTH(ACCWIDTH)) 
+     acc (.clk(clk),.clear(clear),.acc(do_acc),.in(sum_of_prod),.out(acc_out));   
+   // acc_out available on phase_d4
+   
+   wire [ACCWIDTH-6:0] clipped_acc;
+   clip #(.bits_in(ACCWIDTH),.bits_out(ACCWIDTH-5)) final_clip(.in(acc_out),.out(clipped_acc));
+   
+   reg [ACCWIDTH-6:0]   clipped_reg;
+   always @(posedge clk)
+     if(phase_d4 == 4)
+       clipped_reg <= clipped_acc;
+   // clipped_reg available on phase_d5
+   
+   wire [OWIDTH-1:0]   data_out_round;
+   round #(.bits_in(ACCWIDTH-5),.bits_out(OWIDTH)) final_round (.in(clipped_reg),.out(data_out_round));
+
+   reg 		      odd;
+   always @(posedge clk)
+     if(rst)
+       odd <= 0;
+     else if(stb_in)
+       odd <= 0;
+     else if(stb_out)
+       odd <= 1;
+
+   always @(posedge clk)
+     if(bypass)
+       data_out <= data_in;
+     else if(stb_out)
+       if(odd)
+	 data_out <= data_e;
+       else
+	 data_out <= data_out_round;
+
+   // data_out available on phase_d6
+   
+endmodule // hb_interp
diff --git a/usrp2/sdr_lib/hb_interp_tb.v b/usrp2/sdr_lib/hb_interp_tb.v
new file mode 100644
index 000000000..52f137f28
--- /dev/null
+++ b/usrp2/sdr_lib/hb_interp_tb.v
@@ -0,0 +1,132 @@
+module hb_interp_tb( ) ;
+   
+   // Parameters for instantiation
+   parameter               clocks  = 8'd2 ; // Number of clocks per output
+   parameter               decim   = 1 ; // Sets the filter to decimate
+   parameter               rate    = 2 ; // Sets the decimation rate
+   
+   reg                     clock ;
+   reg                     reset ;
+   reg                     enable ;
+   wire 		   strobe_in ;
+   reg 			   signed  [17:0]  data_in ;
+   wire                    strobe_out ;
+   wire 		   signed  [17:0]  data_out ;
+   
+   initial
+     begin
+	$dumpfile("hb_interp_tb.vcd");
+	$dumpvars(0,hb_interp_tb);
+     end
+   
+   // Setup the clock
+   initial clock = 1'b0 ;
+   always #5 clock <= ~clock ;
+   
+   // Come out of reset after a while
+   initial reset = 1'b1 ;
+   initial #1000 reset = 1'b0 ;
+
+   always @(posedge clock)
+     enable <= ~reset;
+   
+   // Instantiate UUT
+   /*
+    halfband_ideal 
+      #(
+        .decim      ( decim         ),
+        .rate       ( rate          )
+      ) uut(
+        .clock      ( clock         ),
+        .reset      ( reset         ),
+        .enable     ( enable        ),
+        .strobe_in  ( strobe_in     ),
+        .data_in    ( data_in       ),
+        .strobe_out ( strobe_out    ),
+        .data_out   ( data_out      )
+      ) ;
+    */
+
+   cic_strober #(.WIDTH(8))
+     out_strober(.clock(clock),.reset(reset),.enable(enable),.rate(clocks),
+		 .strobe_fast(1),.strobe_slow(strobe_out) );
+   
+   cic_strober #(.WIDTH(8))
+     in_strober(.clock(clock),.reset(reset),.enable(enable),.rate(2),
+		.strobe_fast(strobe_out),.strobe_slow(strobe_in) );
+   
+   hb_interp #() uut
+     (.clk(clock),.rst(reset),.bypass(0),.cpo(clocks),.stb_in(strobe_in),.data_in(data_in),
+      .stb_out(strobe_out),/* .output_rate(clocks), */ .data_out(data_out) );
+   
+   integer i, ri, ro, infile, outfile ;
+   
+   always @(posedge clock)
+     begin
+	if(strobe_out)
+	  $display(data_out);
+     end
+   
+   // Setup file IO
+   initial begin
+      infile = $fopen("input.dat","r") ;
+      outfile = $fopen("output.dat","r") ;
+      $timeformat(-9, 2, " ns", 10) ;
+   end
+   
+   reg                 endofsim ;
+   reg 		       signed  [17:0]  compare ;
+   integer             noe ;
+   initial             noe = 0 ;
+   
+   initial begin
+      // Initialize inputs
+      data_in <= 18'd0 ;
+      
+      // Wait for reset to go away
+      @(negedge reset) #0 ;
+      
+      // While we're still simulating ...
+      while( !endofsim ) begin
+	 
+         // Write the input from the file or 0 if EOF...
+         @( negedge clock ) begin
+            if(strobe_in)
+              if( !$feof(infile) )
+                ri <= #1 $fscanf( infile, "%d", data_in ) ;
+              else
+                data_in <= 18'd0 ;
+         end
+      end
+      
+      // Print out the number of errors that occured
+      if( noe )
+        $display( "FAILED: %d errors during simulation", noe ) ;
+      else
+        $display( "PASSED: Simulation successful" ) ;
+      
+      $finish ;
+   end
+   
+   // Output comparison of simulated values versus known good values
+   always @ (posedge clock) begin
+      if( reset )
+        endofsim <= 1'b0 ;
+      else begin
+         if( !$feof(outfile) ) begin
+            if( strobe_out ) begin
+               ro = $fscanf( outfile, "%d\n", compare ) ;
+               if( compare != data_out ) begin
+                  //$display( "%t: %d != %d", $realtime, data_out, compare ) ;
+                  noe = noe + 1 ;
+               end
+            end
+         end else begin
+            // Signal end of simulation when no more outputs
+	    if($feof(infile))
+              endofsim <= 1'b1 ;
+         end
+      end
+   end     
+   
+endmodule // small_hb_int_tb
diff --git a/usrp2/sdr_lib/hb_tb.v b/usrp2/sdr_lib/hb_tb.v
new file mode 100644
index 000000000..7e960fd13
--- /dev/null
+++ b/usrp2/sdr_lib/hb_tb.v
@@ -0,0 +1,155 @@
+
+module hb_tb();
+
+   localparam SWIDTH = 17;
+   localparam CWIDTH = 18;
+   localparam TWIDTH = 20;
+   localparam ACC_WIDTH = 40;
+   
+   reg clk = 0, rst = 1;
+   wire strobe_in, strobe_out;
+   reg [SWIDTH-1:0] sample_in;
+   wire signed [SWIDTH:0] sample_out;
+
+   reg 	       set_stb;
+   reg [7:0]   set_addr;
+   reg [31:0]  set_data;
+
+   localparam  DECIM = 3;
+   
+   initial $dumpfile("hb_tb.vcd");
+   initial $dumpvars(0,hb_tb);
+
+   always #5 clk <= ~clk;
+   initial 
+     begin
+	@(posedge clk);
+	@(negedge clk);
+	rst <= 0;
+     end
+
+   reg [7:0] stb_counter;
+   always @(posedge clk)
+     if(rst)
+       stb_counter <= 0;
+     else
+       if(stb_counter == 0)
+	 stb_counter <= DECIM;
+       else
+	 stb_counter <= stb_counter - 1;
+   assign    strobe_in = (stb_counter == 0);
+   
+   hb_decim #(.SWIDTH(SWIDTH),.CWIDTH(CWIDTH),
+	      .TWIDTH(TWIDTH),.ACC_WIDTH(ACC_WIDTH)) hb_decim
+     (.clk(clk), .rst(rst),
+      .set_stb(set_stb), .set_addr(set_addr), .set_data(set_data),
+      .sample_in(sample_in),
+      .strobe_in(strobe_in),
+      .sample_out(sample_out),
+      .strobe_out(strobe_out)
+      );
+
+   initial
+     begin : load_coeffs
+	@(negedge rst);
+	@(posedge clk);
+	set_addr <= 124;   // load coeffs
+	set_stb <= 1;
+	set_data <= -18'd49;
+	@(posedge clk);
+	set_data <= 18'd165;
+	@(posedge clk);
+	set_data <= -18'd412;
+	@(posedge clk);
+	set_data <= 18'd873;
+	@(posedge clk);
+	set_data <= -18'd1681;
+	@(posedge clk);
+	set_data <= 18'd3135;
+	@(posedge clk);
+	set_data <= -18'd6282;
+	@(posedge clk);
+	set_data <= 18'd20628;
+	@(posedge clk);
+	set_addr <=125;  // load table
+	// { stb_out, accum, load_accum, done, even_addr, odd_addr_a, odd_addr_b, coeff_addr }
+	set_data <= {1'b1,1'b1,1'b0,1'b1,4'd15,4'd15,4'd0,4'd0}; // Phase 8
+	@(posedge clk);
+	set_data <= {1'b0,1'b1,1'b0,1'b0,4'd15,4'd14,4'd1,4'd1}; // Phase 7
+	@(posedge clk);
+	set_data <= {1'b0,1'b1,1'b0,1'b0,4'd15,4'd13,4'd2,4'd2}; // Phase 6
+	@(posedge clk);
+	set_data <= {1'b0,1'b1,1'b0,1'b0,4'd15,4'd12,4'd3,4'd3}; // Phase 5
+	@(posedge clk);
+	set_data <= {1'b0,1'b1,1'b0,1'b0,4'd15,4'd11,4'd4,4'd4}; // Phase 4
+	@(posedge clk);
+	set_data <= {1'b0,1'b1,1'b0,1'b0,4'd15,4'd10,4'd5,4'd5}; // Phase 3
+	@(posedge clk);
+	set_data <= {1'b0,1'b1,1'b0,1'b0,4'd15,4'd9,4'd6,4'd6};  // Phase 2
+	@(posedge clk);
+	set_data <= {1'b0,1'b0,1'b1,1'b0,4'd15,4'd8,4'd7,4'd7};   // Phase 1
+	@(posedge clk);
+	set_data <= {1'b0,1'b0,1'b0,1'b0,4'd15,4'd8,4'd7,4'd7};   // Phase 0
+	@(posedge clk);
+	set_stb <= 0;
+     end // block: load_coeffs
+   
+   initial
+     begin
+	sample_in <= 0;
+	repeat(40)
+	  @(posedge strobe_in);
+	$display("EVEN");
+	sample_in <= 0;
+	repeat(10)
+	  @(posedge strobe_in);
+	sample_in <= 1;
+	@(posedge strobe_in);
+	sample_in <= 0;
+	repeat(40)
+	  @(posedge strobe_in);
+	sample_in <= 1;
+	repeat(40)
+	  @(posedge strobe_in);
+	sample_in <= 0;
+	repeat(60)
+	  @(posedge strobe_in);
+	sample_in <= 1;
+	repeat(2)
+	  @(posedge strobe_in);
+	sample_in <= 0;
+	repeat(60)
+	  @(posedge strobe_in);
+	$display("ODD");
+	sample_in <= 0;
+	repeat(10)
+	  @(posedge strobe_in);
+	sample_in <= 1;
+	@(posedge strobe_in);
+	sample_in <= 0;
+	repeat(40)
+	  @(posedge strobe_in);
+	sample_in <= 1;
+	repeat(40)
+	  @(posedge strobe_in);
+	sample_in <= 0;
+	repeat(60)
+	  @(posedge strobe_in);
+	sample_in <= 1;
+	repeat(2)
+	  @(posedge strobe_in);
+	sample_in <= 0;
+	repeat(60)
+	  @(posedge strobe_in);
+	$finish;
+     end
+
+   always @(posedge clk)
+     if(strobe_in)
+       $display(sample_in);
+   
+      always @(posedge clk)
+	if(strobe_out)
+	  $display("\t",sample_out);
+
+endmodule // hb_tb
diff --git a/usrp2/sdr_lib/input.dat b/usrp2/sdr_lib/input.dat
new file mode 100644
index 000000000..1e649ac2e
--- /dev/null
+++ b/usrp2/sdr_lib/input.dat
@@ -0,0 +1,341 @@
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diff --git a/usrp2/sdr_lib/integrate.v b/usrp2/sdr_lib/integrate.v
new file mode 100644
index 000000000..db33de979
--- /dev/null
+++ b/usrp2/sdr_lib/integrate.v
@@ -0,0 +1,38 @@
+module integrate
+  #(parameter INPUTW = 16,
+    parameter ACCUMW = 32,
+    parameter OUTPUTW = 16)
+
+   (input clk_i,
+    input rst_i,
+    input ena_i,
+
+    input dump_i,
+    input [INPUTW-1:0] data_i,
+
+    output reg stb_o,
+    output reg [OUTPUTW-1:0] integ_o
+   );
+   
+   wire [ACCUMW-1:0] data_ext = {{ACCUMW-INPUTW{data_i[INPUTW-1]}},data_i};
+   reg  [ACCUMW-1:0] accum;
+
+   always @(posedge clk_i)
+     if (rst_i | ~ena_i)
+       begin
+	  accum <= 0;
+	  integ_o <= 0;
+       end
+     else
+       if (dump_i)
+	 begin
+	    integ_o <= accum[ACCUMW-1:ACCUMW-OUTPUTW];
+	    accum <= data_ext;
+	 end
+       else
+	 accum <= accum + data_ext;
+
+   always @(posedge clk_i)
+     stb_o <= dump_i;
+   
+endmodule // integrate
diff --git a/usrp2/sdr_lib/med_hb_int.v b/usrp2/sdr_lib/med_hb_int.v
new file mode 100644
index 000000000..bc8066509
--- /dev/null
+++ b/usrp2/sdr_lib/med_hb_int.v
@@ -0,0 +1,95 @@
+// Medium halfband decimator (intended to be followed by another stage)
+// Implements impulse responses of the form [A 0 B 0 C 0 D 0.5 D 0 C 0 B 0 A]
+//
+// These taps designed by halfgen_test:
+//   2 * 131072 * halfgen_test(.8/8,4,1)
+// -597, 0, 4283, 0, -17516, 0, 79365, 131072, 79365, 0, -17516, 0, 4283, 0, -597
+
+
+module med_hb_int
+  #(parameter WIDTH=18)
+    (input clk,
+     input rst,
+     input bypass,
+     input stb_in,
+     input [WIDTH-1:0] data_in,
+     input [7:0] output_rate,
+     input stb_out,
+     output reg [WIDTH-1:0] data_out);
+
+   localparam coeff_a = -597;
+   localparam coeff_b = 4283;
+   localparam coeff_c = -17516;
+   localparam coeff_d = 79365;
+   
+   reg 	      phase;
+   reg [WIDTH-1:0] d1, d2, d3, d4, d5, d6, d7, d8;
+   
+   localparam 	   MWIDTH = 36;
+   wire [MWIDTH-1:0] prod;
+   
+   reg [6:0] 	     stbin_d;
+   
+   always @(posedge clk)
+     stbin_d <= {stbin_d[5:0],stb_in};
+   
+   always @(posedge clk)
+     if(stb_in)
+       begin
+	  d1 <= data_in;
+	  d2 <= d1;
+	  d3 <= d2;
+	  d4 <= d3;
+	  d5 <= d4;
+	  d6 <= d5;
+	  d7 <= d6;
+	  d8 <= d7;
+       end
+
+   wire [WIDTH-1:0] sum_a, sum_b, sum_c, sum_d;
+   add2_and_round_reg #(.WIDTH(WIDTH)) add_a (.clk(clk),.in1(d1),.in2(d8),.sum(sum_a));
+   add2_and_round_reg #(.WIDTH(WIDTH)) add_b (.clk(clk),.in1(d2),.in2(d7),.sum(sum_b));
+   add2_and_round_reg #(.WIDTH(WIDTH)) add_c (.clk(clk),.in1(d3),.in2(d6),.sum(sum_c));
+   add2_and_round_reg #(.WIDTH(WIDTH)) add_d (.clk(clk),.in1(d4),.in2(d5),.sum(sum_d));
+
+   MULT18X18S mult1(.C(clk), .CE(1), .R(rst), .P(prod1), .A(stbin_d[1] ? coeff_a : coeff_b), 
+		    .B(stbin_d[1] ? sum_a : sum_b) );
+   MULT18X18S mult2(.C(clk), .CE(1), .R(rst), .P(prod2), .A(stbin_d[1] ? coeff_c : coeff_d), 
+		    .B(stbin_d[1] ? sum_c : sum_d) );
+
+   wire [MWIDTH:0] accum;
+   acc #(.IWIDTH(MWIDTH),.OWIDTH(MWIDTH+1)) 
+     acc (.clk(clk),.clear(stbin_d[2]),.acc(|stbin_d[3:2]),.in(prod),.out(accum));
+   
+   wire [WIDTH+2:0] 	 accum_rnd;
+   round_reg #(.bits_in(MWIDTH+1),.bits_out(WIDTH+3))
+     final_round (.clk(clk),.in(accum),.out(accum_rnd));
+
+   wire [WIDTH-1:0] 	 clipped;
+   clip_reg #(.bits_in(WIDTH+3),.bits_out(WIDTH))
+     final_clip (.clk(clk),.in(accum_rnd),.out(clipped));
+
+   reg [WIDTH-1:0] 	 saved, saved_d3;
+   always @(posedge clk)
+     if(stbin_d[6])
+       saved <= clipped;
+
+   always @(posedge clk)
+     if(stbin_d[3])
+       saved_d3 <= d3;
+	   
+   always @(posedge clk)
+     if(bypass)
+       data_out <= data_in;
+     else if(stb_in & stb_out)
+       case(output_rate)
+	 1 : data_out <= d6; 
+	 2 : data_out <= d4;
+	 3, 4, 5, 6, 7 : data_out <= d3;
+	 default : data_out <= d2;
+       endcase // case(output_rate)
+     else if(stb_out)
+       data_out <= saved;
+
+endmodule // small_hb_int
+
diff --git a/usrp2/sdr_lib/output.dat b/usrp2/sdr_lib/output.dat
new file mode 100644
index 000000000..15db3ced4
--- /dev/null
+++ b/usrp2/sdr_lib/output.dat
@@ -0,0 +1,130 @@
+-1390
+0
+1604
+0
+-1896
+0
+2317
+0
+-2979
+0
+4172
+0
+-6953
+0
+20860
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+20860
+0
+-6953
+0
+4172
+0
+-2979
+0
+2317
+0
+-1896
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+1604
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+-1390
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+
diff --git a/usrp2/sdr_lib/round.v b/usrp2/sdr_lib/round.v
new file mode 100644
index 000000000..c4f9ec9cd
--- /dev/null
+++ b/usrp2/sdr_lib/round.v
@@ -0,0 +1,33 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2007 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+// Rounding "macro"
+// Keeps the topmost bits, does proper 2s comp round to zero (unbiased truncation)
+
+module round
+  #(parameter bits_in=0,
+    parameter bits_out=0)
+    (input [bits_in-1:0] in,
+     output [bits_out-1:0] out);
+
+   assign out = in[bits_in-1:bits_in-bits_out] + (in[bits_in-1] & |in[bits_in-bits_out-1:0]);
+   
+endmodule // round
diff --git a/usrp2/sdr_lib/round_reg.v b/usrp2/sdr_lib/round_reg.v
new file mode 100644
index 000000000..aa0972dab
--- /dev/null
+++ b/usrp2/sdr_lib/round_reg.v
@@ -0,0 +1,39 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2008 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+// Rounding "macro"
+// Keeps the topmost bits, does proper 2s comp rounding (round-to-zero)
+
+module round_reg
+  #(parameter bits_in=0,
+    parameter bits_out=0)
+    (input clk,
+     input [bits_in-1:0] in,
+     output reg [bits_out-1:0] out);
+
+   wire [bits_out-1:0] temp;
+
+   round #(.bits_in(bits_in),.bits_out(bits_out)) round (.in(in),.out(temp));
+   
+   always @(posedge clk)
+     out <= temp;
+   
+endmodule // round
diff --git a/usrp2/sdr_lib/rssi.v b/usrp2/sdr_lib/rssi.v
new file mode 100644
index 000000000..e45e2148c
--- /dev/null
+++ b/usrp2/sdr_lib/rssi.v
@@ -0,0 +1,30 @@
+
+
+module rssi (input clock, input reset, input enable,
+	     input [11:0] adc, output [15:0] rssi, output [15:0] over_count);
+
+   wire 		  over_hi = (adc == 12'h7FF);
+   wire 		  over_lo = (adc == 12'h800);
+   wire 		  over = over_hi | over_lo;
+
+   reg [25:0] 		  over_count_int;
+   always @(posedge clock)
+     if(reset | ~enable)
+       over_count_int <= #1 26'd0;
+     else
+       over_count_int <= #1 over_count_int + (over ? 26'd65535 : 26'd0) - over_count_int[25:10];
+   
+   assign      over_count = over_count_int[25:10];
+   
+   wire [11:0] abs_adc = adc[11] ? ~adc : adc;
+
+   reg [25:0]  rssi_int;
+   always @(posedge clock)
+     if(reset | ~enable)
+       rssi_int <= #1 26'd0;
+     else
+       rssi_int <= #1 rssi_int + abs_adc - rssi_int[25:10];
+
+   assign      rssi = rssi_int[25:10];
+   
+endmodule // rssi
diff --git a/usrp2/sdr_lib/rx_control.v b/usrp2/sdr_lib/rx_control.v
new file mode 100644
index 000000000..0adeb0794
--- /dev/null
+++ b/usrp2/sdr_lib/rx_control.v
@@ -0,0 +1,180 @@
+
+`define DSP_CORE_RX_BASE 160
+
+module rx_control
+  #(parameter FIFOSIZE = 10)
+    (input clk, input rst,
+     input set_stb, input [7:0] set_addr, input [31:0] set_data,
+     
+     input [31:0] master_time,
+     output overrun,
+     
+     // To FIFO interface of Buffer Pool
+     output [31:0] wr_dat_o,
+     output [3:0] wr_flags_o,
+     input wr_ready_i,
+     output wr_ready_o,
+
+     // From DSP Core
+     input [31:0] sample,
+     output run,
+     input strobe,
+
+     // FIFO Levels
+     output [15:0] fifo_occupied,
+     output fifo_full,
+     output fifo_empty,
+     
+     // Debug
+     output [31:0] debug_rx
+     );
+
+   wire [31:0] 	   new_time, new_command;
+   wire 	   sc_pre1, clear_overrun;
+   wire [31:0] 	   rcvtime_pre;
+   reg [31:0] 	   rcvtime;
+   wire [8:0] 	   lines_per_frame;
+   wire [20:0] 	   numlines;
+   wire 	   send_imm_pre, chain_pre;
+   reg 		   send_imm, chain;
+   wire 	   full_ctrl, read_ctrl, empty_ctrl, write_ctrl;
+
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+3)) sr_3
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(new_time),.changed(sc_pre1));
+   
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+4)) sr_4
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(new_command),.changed());
+
+   setting_reg #(.my_addr(`DSP_CORE_RX_BASE+5)) sr_5
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(),.changed(clear_overrun));
+
+   reg 	       sc_pre2;
+   always @(posedge clk)
+     sc_pre2 <= sc_pre1;
+   assign      write_ctrl = sc_pre1 & ~sc_pre2;
+   
+   shortfifo #(.WIDTH(64)) commandfifo
+     (.clk(clk),.rst(rst),.clear(clear_overrun),
+      .datain({new_command,new_time}), .write(write_ctrl), .full(full_ctrl),
+      .dataout({send_imm_pre,chain_pre,numlines,lines_per_frame,rcvtime_pre}), 
+      .read(read_ctrl), .empty(empty_ctrl) );
+
+   // Buffer interface to internal FIFO
+   wire        have_space, write;
+   wire [35:0] fifo_line;
+   
+   // Internal FIFO, size 9 is 2K, size 10 is 4K
+   fifo_cascade #(.WIDTH(36),.SIZE(FIFOSIZE)) rxfifo
+     (.clk(clk),.reset(rst),.clear(clear_overrun),
+      .datain(fifo_line), .src_rdy_i(write), .dst_rdy_o(have_space),
+      .dataout({wr_flags_o,wr_dat_o}), .src_rdy_o(wr_ready_o), .dst_rdy_i(wr_ready_i),
+      .space(),.occupied(fifo_occupied) );
+   assign      fifo_full = ~have_space;
+   assign      fifo_empty = ~wr_ready_o;
+
+   // Internal FIFO to DSP interface
+   reg [22:0] lines_left;
+   reg [8:0]  lines_left_frame;
+   localparam IBS_IDLE = 0;
+   localparam IBS_WAITING = 1;
+   localparam IBS_FIRSTLINE = 2;
+   localparam IBS_RUNNING = 3;
+   localparam IBS_OVERRUN = 4;
+   
+   reg [2:0] ibs_state;
+  
+   wire [32:0] delta_time = {1'b0,rcvtime}-{1'b0,master_time};
+   wire        too_late = (delta_time[32:31] == 2'b11) & ~send_imm;
+   wire        go_now = send_imm | ( master_time == rcvtime );
+ 
+   always @(posedge clk)
+     if(rst)
+       begin
+	  ibs_state <= IBS_IDLE;
+	  lines_left <= 0;
+	  lines_left_frame <= 0;
+	  rcvtime <= 0;
+	  send_imm <= 0;
+	  chain <= 0;
+       end
+     else
+       if(clear_overrun)
+	 begin
+	  ibs_state <= IBS_IDLE;
+	  lines_left <= 0;
+	  lines_left_frame <= 0;
+	  rcvtime <= 0;
+	  send_imm <= 0;
+	  chain <= 0;
+	 end
+       else 
+	 case(ibs_state)
+	   IBS_IDLE :
+	     if(~empty_ctrl)
+	       begin
+		  lines_left <= numlines;
+		  lines_left_frame <= lines_per_frame;
+		  rcvtime <= rcvtime_pre;
+		  ibs_state <= IBS_WAITING;
+		  send_imm <= send_imm_pre;
+		  chain <= chain_pre;
+	       end
+	   IBS_WAITING :
+	     if(go_now)
+	       ibs_state <= IBS_FIRSTLINE;
+	     else if(too_late)
+	       ibs_state <= IBS_OVERRUN;
+	   IBS_FIRSTLINE :
+	     if(~have_space | strobe)
+	       ibs_state <= IBS_OVERRUN;
+	     else
+	       ibs_state <= IBS_RUNNING;
+	   IBS_RUNNING :
+	     if(strobe)
+	       if(~have_space)
+		 ibs_state <= IBS_OVERRUN;
+	       else
+		 begin
+		    lines_left <= lines_left - 1;
+		    if(lines_left == 1)
+		      if(~chain)
+			ibs_state <= IBS_IDLE;
+		      else if(empty_ctrl)
+			ibs_state <= IBS_OVERRUN;
+		      else
+			begin
+			   lines_left <= numlines;
+			   lines_left_frame <= lines_per_frame;
+			   rcvtime <= rcvtime_pre;
+			   ibs_state <= IBS_FIRSTLINE;
+			   send_imm <= send_imm_pre;
+			   chain <= chain_pre;
+			end
+		    else if(lines_left_frame == 1)
+		      begin
+			 lines_left_frame <= lines_per_frame;
+			 ibs_state <= IBS_FIRSTLINE;
+		      end
+		    else
+		      lines_left_frame <= lines_left_frame - 1;
+		 end // else: !if(~have_space)
+	 endcase // case(ibs_state)
+   
+   assign fifo_line = (ibs_state == IBS_FIRSTLINE) ? {2'b0,1'b0,1'b1,master_time} :
+		      {2'b0,((lines_left==1)|(lines_left_frame==1)),1'b0,sample};
+   
+   assign write = ((ibs_state == IBS_FIRSTLINE) | strobe) & have_space;  // & (ibs_state == IBS_RUNNING) should strobe only when running
+   assign overrun = (ibs_state == IBS_OVERRUN);
+   assign run = (ibs_state == IBS_RUNNING) | (ibs_state == IBS_FIRSTLINE);
+   assign read_ctrl = ( (ibs_state == IBS_IDLE) | 
+			((ibs_state == IBS_RUNNING) & strobe & have_space & (lines_left==1) & chain) )
+	  & ~empty_ctrl;
+   
+   assign debug_rx = { 8'd0,
+		       1'd0, send_imm, chain, wr_ready_i,wr_ready_o, 2'b0, run,
+		       write,have_space,wr_flags_o[1:0],write_ctrl,full_ctrl,read_ctrl,empty_ctrl,
+		       sc_pre1, clear_overrun, go_now, too_late, overrun, ibs_state[2:0] };
+endmodule // rx_control
diff --git a/usrp2/sdr_lib/rx_dcoffset.v b/usrp2/sdr_lib/rx_dcoffset.v
new file mode 100644
index 000000000..bedbd40e6
--- /dev/null
+++ b/usrp2/sdr_lib/rx_dcoffset.v
@@ -0,0 +1,43 @@
+
+
+module rx_dcoffset 
+  #(parameter WIDTH=14,
+    parameter ADDR=8'd0)
+    (input clk, input rst, 
+     input set_stb, input [7:0] set_addr, input [31:0] set_data,
+     input signed [WIDTH-1:0] adc_in, output signed [WIDTH-1:0] adc_out);
+
+   // Because of some extra delays to make timing easier, the transfer function is:
+   //     (z-1)/(z^2-z-alpha)  where alpha is 1/2^n
+   
+   wire 	       set_now = set_stb & (ADDR == set_addr);
+   
+   reg 		       fixed;  // uses fixed offset
+   wire 	       signed [WIDTH-1:0] fixed_dco;
+   reg 		       signed [31:0] integrator;
+
+   always @(posedge clk)
+     if(rst)
+       begin
+	  fixed <= 0;
+	  integrator <= 32'd0;
+       end
+     else if(set_now)
+       begin
+	  integrator <= {set_data[WIDTH-1:0],{(32-WIDTH){1'b0}}};
+	  fixed <= set_data[31];
+       end
+     else if(~fixed)
+       integrator <= integrator + adc_out;
+   
+   wire [WIDTH:0] scaled_integrator;
+   
+   round #(.bits_in(33),.bits_out(15)) round (.in({integrator[31],integrator}),.out(scaled_integrator));
+   
+   wire [WIDTH:0]      adc_out_int = {adc_in[WIDTH-1],adc_in} - scaled_integrator;
+
+   clip_reg #(.bits_in(WIDTH+1),.bits_out(WIDTH)) clip_adc
+     (.clk(clk),.in(adc_out_int),.out(adc_out));
+   
+
+endmodule // rx_dcoffset
diff --git a/usrp2/sdr_lib/rx_dcoffset_tb.v b/usrp2/sdr_lib/rx_dcoffset_tb.v
new file mode 100644
index 000000000..a8b4ec20f
--- /dev/null
+++ b/usrp2/sdr_lib/rx_dcoffset_tb.v
@@ -0,0 +1,25 @@
+
+`timescale 1ns/1ns
+module rx_dcoffset_tb();
+   
+   reg clk, rst;
+
+   initial rst = 1;
+   initial #1000 rst = 0;
+   initial clk = 0;
+   always #5 clk = ~clk;
+   
+   initial $dumpfile("rx_dcoffset_tb.vcd");
+   initial $dumpvars(0,rx_dcoffset_tb);
+
+   reg [13:0] adc_in = 7;
+   wire [13:0] adc_out;
+
+   always @(posedge clk)
+     $display("%d\t%d",adc_in,adc_out);
+   
+   rx_dcoffset #(.WIDTH(14),.ADDR(0))
+     rx_dcoffset(.clk(clk),.rst(rst),.set_stb(0),.set_addr(0),.set_data(0),
+		 .adc_in(adc_in),.adc_out(adc_out));
+   
+endmodule // longfifo_tb
diff --git a/usrp2/sdr_lib/sign_extend.v b/usrp2/sdr_lib/sign_extend.v
new file mode 100644
index 000000000..eae67faf2
--- /dev/null
+++ b/usrp2/sdr_lib/sign_extend.v
@@ -0,0 +1,35 @@
+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2003 Matt Ettus
+//
+//  This program is free software; you can redistribute it and/or modify
+//  it under the terms of the GNU General Public License as published by
+//  the Free Software Foundation; either version 2 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU General Public License for more details.
+//
+//  You should have received a copy of the GNU General Public License
+//  along with this program; if not, write to the Free Software
+//  Foundation, Inc., 51 Franklin Street, Boston, MA  02110-1301  USA
+//
+
+
+// Sign extension "macro"
+// bits_out should be greater than bits_in
+
+module sign_extend (in,out);
+	parameter bits_in=0;  // FIXME Quartus insists on a default
+	parameter bits_out=0;
+	
+	input [bits_in-1:0] in;
+	output [bits_out-1:0] out;
+	
+	assign out = {{(bits_out-bits_in){in[bits_in-1]}},in};
+	
+endmodule
diff --git a/usrp2/sdr_lib/small_hb_dec.v b/usrp2/sdr_lib/small_hb_dec.v
new file mode 100644
index 000000000..8519b628a
--- /dev/null
+++ b/usrp2/sdr_lib/small_hb_dec.v
@@ -0,0 +1,111 @@
+// Short halfband decimator (intended to be followed by another stage)
+// Implements impulse responses of the form [A 0 B 0.5 B 0 A]
+//
+// These taps designed by halfgen4 from ldoolittle:
+//   2 * 131072 * halfgen4(.75/8,2)
+module small_hb_dec
+  #(parameter WIDTH=18)
+    (input clk,
+     input rst,
+     input bypass,
+     input run,
+     input stb_in,
+     input [WIDTH-1:0] data_in,
+     output reg stb_out,
+     output [WIDTH-1:0] data_out);
+
+   reg 			stb_in_d1;
+   reg [WIDTH-1:0] 	data_in_d1;
+   always @(posedge clk) stb_in_d1 <= stb_in;
+   always @(posedge clk) data_in_d1 <= data_in;
+   
+   wire 		go;
+   reg 			phase, go_d1, go_d2, go_d3, go_d4;
+   always @(posedge clk)
+     if(rst | ~run)
+       phase <= 0;
+     else if(stb_in_d1)
+       phase <= ~phase;
+   assign 		go = stb_in_d1 & phase;
+   always @(posedge clk) 
+     if(rst | ~run)
+       begin
+	  go_d1 <= 0;
+	  go_d2 <= 0;
+	  go_d3 <= 0;
+	  go_d4 <= 0;
+       end
+     else
+       begin
+	  go_d1 <= go;
+	  go_d2 <= go_d1;
+	  go_d3 <= go_d2;
+	  go_d4 <= go_d3;
+       end
+
+   wire [17:0] 		coeff_a = -10690;
+   wire [17:0] 		coeff_b = 75809;
+   
+   reg [WIDTH-1:0] 	d1, d2, d3, d4 , d5, d6;
+   always @(posedge clk)
+     if(stb_in_d1 | rst)
+       begin
+	  d1 <= data_in_d1;
+	  d2 <= d1;
+	  d3 <= d2;
+	  d4 <= d3;
+	  d5 <= d4;
+	  d6 <= d5;
+       end
+
+   reg [17:0] sum_a, sum_b, middle, middle_d1;
+   wire [17:0] sum_a_unreg, sum_b_unreg;
+   add2 #(.WIDTH(18)) add2_a (.in1(data_in_d1),.in2(d6),.sum(sum_a_unreg));
+   add2 #(.WIDTH(18)) add2_b (.in1(d2),.in2(d4),.sum(sum_b_unreg));
+   
+   always @(posedge clk)
+     if(go)
+       begin
+	  sum_a <= sum_a_unreg;
+	  sum_b <= sum_b_unreg;
+	  middle <= d3;
+       end
+
+   always @(posedge clk)
+     if(go_d1)
+       middle_d1 <= middle;
+   
+   wire [17:0] sum = go_d1 ? sum_b : sum_a;
+   wire [17:0] coeff = go_d1 ? coeff_b : coeff_a;
+   wire [35:0] 	 prod;   
+   MULT18X18S mult(.C(clk), .CE(go_d1 | go_d2), .R(rst), .P(prod), .A(coeff), .B(sum) );
+   
+   reg [35:0] 	 accum;
+   always @(posedge clk)
+     if(rst)
+       accum <= 0;
+     else if(go_d2)
+       accum <= {middle_d1[17],middle_d1[17],middle_d1,16'd0} + {prod};
+     else if(go_d3)
+       accum <= accum + {prod};
+   
+   wire [17:0] 	 accum_rnd;
+   round #(.bits_in(36),.bits_out(18)) round_acc (.in(accum),.out(accum_rnd));
+
+   reg [17:0] 	 final_sum;
+   always @(posedge clk)
+     if(bypass)
+       final_sum <= data_in_d1;
+     else if(go_d4)
+       final_sum <= accum_rnd;
+
+   assign 	 data_out = final_sum;
+
+   always @(posedge clk)
+     if(rst)
+       stb_out <= 0;
+     else if(bypass)
+       stb_out <= stb_in_d1;
+     else
+       stb_out <= go_d4;
+endmodule // small_hb_dec
diff --git a/usrp2/sdr_lib/small_hb_dec_tb.v b/usrp2/sdr_lib/small_hb_dec_tb.v
new file mode 100644
index 000000000..0d6a0689e
--- /dev/null
+++ b/usrp2/sdr_lib/small_hb_dec_tb.v
@@ -0,0 +1,140 @@
+module hb_dec_tb( ) ;
+   
+    // Parameters for instantiation
+    parameter               clocks  = 9'd2 ; // Number of clocks per input
+    parameter               decim   = 1 ; // Sets the filter to decimate
+    parameter               rate    = 2 ; // Sets the decimation rate
+
+    reg                     clock ;
+    reg                     reset ;
+    reg                     enable ;
+    reg                     strobe_in ;
+    reg     signed  [17:0]  data_in ;
+    wire                    strobe_out ;
+    wire    signed  [17:0]  data_out ;
+
+   initial
+     begin
+	$dumpfile("hb_dec_tb.vcd");
+	$dumpvars(0,hb_dec_tb);
+     end
+   
+    // Setup the clock
+    initial clock = 1'b0 ;
+    always #5 clock <= ~clock ;
+
+    // Come out of reset after a while
+    initial reset = 1'b1 ;
+    initial #1000 reset = 1'b0 ;
+
+    // Enable the entire system
+    initial enable = 1'b1 ;
+
+    // Instantiate UUT
+   /*
+    halfband_ideal 
+      #(
+        .decim      ( decim         ),
+        .rate       ( rate          )
+      ) uut(
+        .clock      ( clock         ),
+        .reset      ( reset         ),
+        .enable     ( enable        ),
+        .strobe_in  ( strobe_in     ),
+        .data_in    ( data_in       ),
+        .strobe_out ( strobe_out    ),
+        .data_out   ( data_out      )
+      ) ;
+    */
+
+   
+   small_hb_dec #(.WIDTH(18)) uut
+     (.clk(clock),.rst(reset),.bypass(0),.stb_in(strobe_in),.data_in(data_in),
+      .stb_out(strobe_out),.data_out(data_out) );
+   
+    integer i, ri, ro, infile, outfile ;
+
+   always @(posedge clock)
+     begin
+	if(strobe_out)
+	  $display(data_out);
+     end
+   
+    // Setup file IO
+    initial begin
+        infile = $fopen("input.dat","r") ;
+        outfile = $fopen("output.dat","r") ;
+        $timeformat(-9, 2, " ns", 10) ;
+    end
+
+    reg                 endofsim ;
+    reg signed  [17:0]  compare ;
+    integer             noe ;
+    initial             noe = 0 ;
+
+    initial begin
+        // Initialize inputs
+        strobe_in <= 1'd0 ;
+        data_in <= 18'd0 ;
+
+        // Wait for reset to go away
+        @(negedge reset) #0 ;
+        
+        // While we're still simulating ...
+        while( !endofsim ) begin
+
+            // Write the input from the file or 0 if EOF...
+            @( posedge clock ) begin
+               //#1 ;
+                strobe_in <= 1'b1 ;
+                if( !$feof(infile) )
+                    ri = $fscanf( infile, "%d", data_in ) ;
+                else
+                    data_in <= 18'd0 ;
+            end
+
+            // Clocked in - set the strobe to 0 if the number of
+            // clocks per sample is greater than 1
+            if( clocks > 1 ) begin
+                @(posedge clock) begin
+                    strobe_in <= 1'b0  ;
+                end
+
+                // Wait for the specified number of cycles
+                for( i = 0 ; i < (clocks-2) ; i = i + 1 ) begin
+                    @(posedge clock) #1 ;
+                end
+            end
+        end
+
+        // Print out the number of errors that occured
+        if( noe )
+            $display( "FAILED: %d errors during simulation", noe ) ;
+        else
+            $display( "PASSED: Simulation successful" ) ;
+
+        $finish ;
+    end
+
+   // Output comparison of simulated values versus known good values
+   always @ (posedge clock) begin
+      if( reset )
+        endofsim <= 1'b0 ;
+      else begin
+         if( !$feof(outfile) ) begin
+            if( strobe_out ) begin
+               ro = $fscanf( outfile, "%d\n", compare ) ;
+               if( compare != data_out ) begin
+                  //$display( "%t: %d != %d", $realtime, data_out, compare ) ;
+                  noe = noe + 1 ;
+               end
+            end
+         end else begin
+            // Signal end of simulation when no more outputs
+            endofsim <= 1'b1 ;
+         end
+      end
+   end     
+
+endmodule // hb_dec_tb
+
diff --git a/usrp2/sdr_lib/small_hb_int.v b/usrp2/sdr_lib/small_hb_int.v
new file mode 100644
index 000000000..f80d3cac3
--- /dev/null
+++ b/usrp2/sdr_lib/small_hb_int.v
@@ -0,0 +1,85 @@
+// Short halfband decimator (intended to be followed by another stage)
+// Implements impulse responses of the form [A 0 B 0.5 B 0 A]
+//
+// These taps designed by halfgen4 from ldoolittle:
+//   2 * 131072 * halfgen4(.75/8,2)
+
+module small_hb_int
+  #(parameter WIDTH=18)
+    (input clk,
+     input rst,
+     input bypass,
+     input stb_in,
+     input [WIDTH-1:0] data_in,
+     input [7:0] output_rate,
+     input stb_out,
+     output reg [WIDTH-1:0] data_out);
+
+   reg 		   phase;
+   reg [WIDTH-1:0] d1, d2, d3, d4, d5, d6;
+
+   localparam 	   MWIDTH = 36;
+   wire [MWIDTH-1:0] prod;
+
+   reg [6:0] 	     stbin_d;
+   
+   always @(posedge clk)
+     stbin_d <= {stbin_d[5:0],stb_in};
+   
+   always @(posedge clk)
+     if(stb_in)
+       begin
+	  d1 <= data_in;
+	  d2 <= d1;
+	  d3 <= d2;
+	  d4 <= d3;
+	  d5 <= d4;
+	  d6 <= d5;
+       end
+
+   wire [WIDTH-1:0] sum_outer, sum_inner;
+   add2_and_round_reg #(.WIDTH(WIDTH)) add_outer (.clk(clk),.in1(d1),.in2(d4),.sum(sum_outer));
+   add2_and_round_reg #(.WIDTH(WIDTH)) add_inner (.clk(clk),.in1(d2),.in2(d3),.sum(sum_inner));
+
+   wire [17:0] 	   coeff_outer = -10690;
+   wire [17:0] 	   coeff_inner = 75809;
+
+   MULT18X18S mult(.C(clk), .CE(1), .R(rst), .P(prod), .A(stbin_d[1] ? coeff_outer : coeff_inner), 
+		   .B(stbin_d[1] ? sum_outer : sum_inner) );
+
+   wire [MWIDTH:0] accum;
+   acc #(.IWIDTH(MWIDTH),.OWIDTH(MWIDTH+1)) 
+     acc (.clk(clk),.clear(stbin_d[2]),.acc(|stbin_d[3:2]),.in(prod),.out(accum));
+   
+   wire [WIDTH+2:0] 	 accum_rnd;
+   round_reg #(.bits_in(MWIDTH+1),.bits_out(WIDTH+3))
+     final_round (.clk(clk),.in(accum),.out(accum_rnd));
+
+   wire [WIDTH-1:0] 	 clipped;
+   clip_reg #(.bits_in(WIDTH+3),.bits_out(WIDTH))
+     final_clip (.clk(clk),.in(accum_rnd),.out(clipped));
+
+   reg [WIDTH-1:0] 	 saved, saved_d3;
+   always @(posedge clk)
+     if(stbin_d[6])
+       saved <= clipped;
+
+   always @(posedge clk)
+     if(stbin_d[3])
+       saved_d3 <= d3;
+	   
+   always @(posedge clk)
+     if(bypass)
+       data_out <= data_in;
+     else if(stb_in & stb_out)
+       case(output_rate)
+	 1 : data_out <= d6; 
+	 2 : data_out <= d4;
+	 3, 4, 5, 6, 7 : data_out <= d3;
+	 default : data_out <= d2;
+       endcase // case(output_rate)
+     else if(stb_out)
+       data_out <= saved;
+
+endmodule // small_hb_int
+
diff --git a/usrp2/sdr_lib/small_hb_int_tb.v b/usrp2/sdr_lib/small_hb_int_tb.v
new file mode 100644
index 000000000..71d77f0a8
--- /dev/null
+++ b/usrp2/sdr_lib/small_hb_int_tb.v
@@ -0,0 +1,132 @@
+module small_hb_int_tb( ) ;
+   
+   // Parameters for instantiation
+   parameter               clocks  = 8'd1 ; // Number of clocks per output
+   parameter               decim   = 1 ; // Sets the filter to decimate
+   parameter               rate    = 2 ; // Sets the decimation rate
+   
+   reg                     clock ;
+   reg                     reset ;
+   reg                     enable ;
+   wire 		   strobe_in ;
+   reg 			   signed  [17:0]  data_in ;
+   wire                    strobe_out ;
+   wire 		   signed  [17:0]  data_out ;
+   
+   initial
+     begin
+	$dumpfile("small_hb_int_tb.vcd");
+	$dumpvars(0,small_hb_int_tb);
+     end
+   
+   // Setup the clock
+   initial clock = 1'b0 ;
+   always #5 clock <= ~clock ;
+   
+   // Come out of reset after a while
+   initial reset = 1'b1 ;
+   initial #1000 reset = 1'b0 ;
+
+   always @(posedge clock)
+     enable <= ~reset;
+   
+   // Instantiate UUT
+   /*
+    halfband_ideal 
+      #(
+        .decim      ( decim         ),
+        .rate       ( rate          )
+      ) uut(
+        .clock      ( clock         ),
+        .reset      ( reset         ),
+        .enable     ( enable        ),
+        .strobe_in  ( strobe_in     ),
+        .data_in    ( data_in       ),
+        .strobe_out ( strobe_out    ),
+        .data_out   ( data_out      )
+      ) ;
+    */
+
+   cic_strober #(.WIDTH(8))
+     out_strober(.clock(clock),.reset(reset),.enable(enable),.rate(clocks),
+		 .strobe_fast(1),.strobe_slow(strobe_out) );
+   
+   cic_strober #(.WIDTH(8))
+     in_strober(.clock(clock),.reset(reset),.enable(enable),.rate(2),
+		.strobe_fast(strobe_out),.strobe_slow(strobe_in) );
+   
+   small_hb_int #(.WIDTH(18)) uut
+     (.clk(clock),.rst(reset),.bypass(0),.stb_in(strobe_in),.data_in(data_in),
+      .stb_out(strobe_out),.output_rate(clocks),.data_out(data_out) );
+   
+   integer i, ri, ro, infile, outfile ;
+   
+   always @(posedge clock)
+     begin
+	if(strobe_out)
+	  $display(data_out);
+     end
+   
+   // Setup file IO
+   initial begin
+      infile = $fopen("input.dat","r") ;
+      outfile = $fopen("output.dat","r") ;
+      $timeformat(-9, 2, " ns", 10) ;
+   end
+   
+   reg                 endofsim ;
+   reg 		       signed  [17:0]  compare ;
+   integer             noe ;
+   initial             noe = 0 ;
+   
+   initial begin
+      // Initialize inputs
+      data_in <= 18'd0 ;
+      
+      // Wait for reset to go away
+      @(negedge reset) #0 ;
+      
+      // While we're still simulating ...
+      while( !endofsim ) begin
+	 
+         // Write the input from the file or 0 if EOF...
+         @( negedge clock ) begin
+            if(strobe_in)
+              if( !$feof(infile) )
+                ri <= #1 $fscanf( infile, "%d", data_in ) ;
+              else
+                data_in <= 18'd0 ;
+         end
+      end
+      
+      // Print out the number of errors that occured
+      if( noe )
+        $display( "FAILED: %d errors during simulation", noe ) ;
+      else
+        $display( "PASSED: Simulation successful" ) ;
+      
+      $finish ;
+   end
+   
+   // Output comparison of simulated values versus known good values
+   always @ (posedge clock) begin
+      if( reset )
+        endofsim <= 1'b0 ;
+      else begin
+         if( !$feof(outfile) ) begin
+            if( strobe_out ) begin
+               ro = $fscanf( outfile, "%d\n", compare ) ;
+               if( compare != data_out ) begin
+                  //$display( "%t: %d != %d", $realtime, data_out, compare ) ;
+                  noe = noe + 1 ;
+               end
+            end
+         end else begin
+            // Signal end of simulation when no more outputs
+	    if($feof(infile))
+              endofsim <= 1'b1 ;
+         end
+      end
+   end     
+   
+endmodule // small_hb_int_tb
diff --git a/usrp2/sdr_lib/tx_control.v b/usrp2/sdr_lib/tx_control.v
new file mode 100644
index 000000000..e5fed0b93
--- /dev/null
+++ b/usrp2/sdr_lib/tx_control.v
@@ -0,0 +1,168 @@
+
+`define DSP_CORE_TX_BASE 128
+
+module tx_control
+  #(parameter FIFOSIZE = 10)
+    (input clk, input rst,
+     input set_stb, input [7:0] set_addr, input [31:0] set_data,
+     
+     input [31:0] master_time, 
+     output underrun,
+     
+     // To FIFO interface from Buffer Pool
+     input [31:0] rd_dat_i,
+     input [3:0] rd_flags_i,
+     input rd_ready_i,
+     output rd_ready_o,
+     
+     // To DSP Core
+     output [31:0] sample,
+     output run,
+     input strobe,
+
+     // FIFO Levels
+     output [15:0] fifo_occupied,
+     output fifo_full,
+     output fifo_empty,
+
+     // Debug
+     output [31:0] debug
+     );
+
+   wire 	   rd_sop_i  = rd_flags_i[0];  // Unused
+   wire 	   rd_eop_i  = rd_flags_i[1];
+   wire 	   rd_occ_i = rd_flags_i[3:2]; // Unused, should always be 0
+
+   // Buffer interface to internal FIFO
+   wire     write_data, write_ctrl, full_data, full_ctrl;
+   wire     read_data, read_ctrl, empty_data, empty_ctrl;
+   wire     clear_state;
+   reg [1:0] xfer_state;
+   reg [2:0] held_flags;
+   
+   localparam XFER_IDLE = 0;
+   localparam XFER_CTRL = 1;
+   localparam XFER_PKT = 2;
+   // Add underrun state?
+   
+   always @(posedge clk)
+     if(rst)
+       xfer_state <= XFER_IDLE;
+     else if(clear_state)
+       xfer_state <= XFER_IDLE;
+     else
+       if(rd_ready_i & rd_ready_o)
+	 case(xfer_state)
+	   XFER_IDLE :
+	     begin
+		xfer_state <= XFER_CTRL;
+		held_flags <= rd_dat_i[2:0];
+	     end
+	   XFER_CTRL :
+	     xfer_state <= XFER_PKT;
+	   XFER_PKT :
+	     if(rd_eop_i)
+	       xfer_state <= XFER_IDLE;
+	 endcase // case(xfer_state)
+
+   wire have_data_space;
+   assign full_data   = ~have_data_space;
+   
+   assign write_data  = (xfer_state == XFER_PKT) & rd_ready_i & rd_ready_o;
+   assign write_ctrl  = (xfer_state == XFER_CTRL) & rd_ready_i & rd_ready_o;
+
+   assign rd_ready_o  = ~full_data & ~full_ctrl;
+   
+   wire [31:0] data_o;
+   wire        eop_o, eob, sob, send_imm;
+   wire [31:0] sendtime;
+   wire [4:0]  occ_ctrl;
+/*   
+   cascadefifo2 #(.WIDTH(33),.SIZE(FIFOSIZE)) txctrlfifo
+     (.clk(clk),.rst(rst),.clear(clear_state),
+      .datain({rd_eop_i,rd_dat_i[31:0]}), .write(write_data), .full(full_data),
+      .dataout({eop_o,data_o}), .read(read_data), .empty(empty_data),
+      .space(), .occupied(fifo_occupied) );
+*/
+   wire        have_data;
+   assign empty_data  = ~have_data;
+   
+   fifo_cascade #(.WIDTH(33),.SIZE(FIFOSIZE)) txctrlfifo
+     (.clk(clk),.reset(rst),.clear(clear_state),
+      .datain({rd_eop_i,rd_dat_i[31:0]}), .src_rdy_i(write_data), .dst_rdy_o(have_data_space),
+      .dataout({eop_o,data_o}), .src_rdy_o(have_data), .dst_rdy_i(read_data),
+      .space(), .occupied(fifo_occupied) );
+   assign      fifo_full = full_data;
+   assign      fifo_empty = empty_data;
+
+   shortfifo #(.WIDTH(35)) ctrlfifo
+     (.clk(clk),.rst(rst),.clear(clear_state),
+      .datain({held_flags[2:0],rd_dat_i[31:0]}), .write(write_ctrl), .full(full_ctrl),
+      .dataout({send_imm,sob,eob,sendtime}), .read(read_ctrl), .empty(empty_ctrl),
+      .space(), .occupied(occ_ctrl) );
+
+   // Internal FIFO to DSP interface
+   reg [2:0]   ibs_state;
+   
+   localparam  IBS_IDLE = 0;
+   localparam  IBS_WAIT = 1;
+   localparam  IBS_RUNNING = 2;
+   localparam  IBS_CONT_BURST = 3;
+   localparam  IBS_UNDERRUN = 7;
+
+   wire [32:0] delta_time = {1'b0,sendtime}-{1'b0,master_time};
+   
+   wire        too_late = (delta_time[32:31] == 2'b11);
+   wire        go_now = ( master_time == sendtime );
+   
+   always @(posedge clk)
+     if(rst)
+       ibs_state <= IBS_IDLE;
+     else
+       case(ibs_state)
+	 IBS_IDLE :
+	   if(~empty_ctrl & ~empty_data)
+	     ibs_state <= IBS_WAIT;
+	 IBS_WAIT :
+	   if(send_imm)
+	     ibs_state <= IBS_RUNNING;
+	   else if(too_late)
+	     ibs_state <= IBS_UNDERRUN;
+	   else if(go_now)
+	     ibs_state <= IBS_RUNNING;
+	 IBS_RUNNING :
+	   if(strobe)
+	     if(empty_data)
+	       ibs_state <= IBS_UNDERRUN;
+	     else if(eop_o)
+	       if(eob)
+		 ibs_state <= IBS_IDLE;
+	       else
+		 ibs_state <= IBS_CONT_BURST;
+	 IBS_CONT_BURST :
+	   if(~empty_ctrl)  //  & ~empty_data)
+	     ibs_state <= IBS_RUNNING;
+	   else if(strobe)
+	     ibs_state <= IBS_UNDERRUN;
+	 IBS_UNDERRUN :   // FIXME Should probably clean everything out
+	   if(clear_state)
+	     ibs_state <= IBS_IDLE;
+       endcase // case(ibs_state)
+
+   assign      read_ctrl = (ibs_state == IBS_RUNNING) & strobe & eop_o;  // & ~empty_ctrl;
+   assign      read_data = (ibs_state == IBS_RUNNING) & strobe & ~empty_data;
+   assign      run = (ibs_state == IBS_RUNNING) | (ibs_state == IBS_CONT_BURST);
+   assign      underrun = (ibs_state == IBS_UNDERRUN);
+
+   wire [7:0]  interp_rate;
+   setting_reg #(.my_addr(`DSP_CORE_TX_BASE+3)) sr_3
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(),.changed(clear_state));
+
+   assign      sample = data_o;
+
+   assign      debug = { {16'b0},
+			 { read_data, write_data, read_ctrl, write_ctrl, xfer_state[1:0],full_ctrl,empty_ctrl },
+			 { occ_ctrl, eop_o, clear_state, underrun} };
+   
+endmodule // tx_control