1 files changed, 121 insertions, 0 deletions
diff --git a/fpga/usrp2/sdr_lib/hb/halfband_interp.v b/fpga/usrp2/sdr_lib/hb/halfband_interp.v
new file mode 100644
index 000000000..cdb11c1f6
--- /dev/null
+++ b/fpga/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