From 05d77f772317de5d925301aa11bb9a880656dd05 Mon Sep 17 00:00:00 2001
From: Josh Blum <josh@joshknows.com>
Date: Thu, 15 Apr 2010 11:24:24 -0700
Subject: moved usrp1 and usrp2 fpga dirs into fpga subdirectory

---
 fpga/usrp1/sdr_lib/rx_chain_dual.v | 103 +++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 fpga/usrp1/sdr_lib/rx_chain_dual.v

(limited to 'fpga/usrp1/sdr_lib/rx_chain_dual.v')

diff --git a/fpga/usrp1/sdr_lib/rx_chain_dual.v b/fpga/usrp1/sdr_lib/rx_chain_dual.v
new file mode 100644
index 000000000..d9d98f3fc
--- /dev/null
+++ b/fpga/usrp1/sdr_lib/rx_chain_dual.v
@@ -0,0 +1,103 @@
+// -*- 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 rx_chain_dual
+  (input clock,
+   input clock_2x,
+   input reset,
+   input enable,
+   input wire [7:0] decim_rate,
+   input sample_strobe,
+   input decimator_strobe,
+   input wire [31:0] freq0,
+   input wire [15:0] i_in0,
+   input wire [15:0] q_in0,
+   output wire [15:0] i_out0,
+   output wire [15:0] q_out0,
+   input wire [31:0] freq1,
+   input wire [15:0] i_in1,
+   input wire [15:0] q_in1,
+   output wire [15:0] i_out1,
+   output wire [15:0] q_out1
+   );
+
+   wire [15:0] phase;
+   wire [15:0] bb_i, bb_q;
+   wire [15:0] i_in, q_in;
+   
+   wire [31:0] phase0;
+   wire [31:0] phase1;
+   reg [15:0] bb_i0, bb_q0;
+   reg [15:0] bb_i1, bb_q1;
+
+   // We want to time-share the CORDIC by double-clocking it
+   
+   phase_acc rx_phase_acc_0
+     (.clk(clock),.reset(reset),.enable(enable),
+      .strobe(sample_strobe),.freq(freq0),.phase(phase0) );
+
+   phase_acc rx_phase_acc_1
+     (.clk(clock),.reset(reset),.enable(enable),
+      .strobe(sample_strobe),.freq(freq1),.phase(phase1) );
+   
+   assign phase = clock ? phase0[31:16] : phase1[31:16];
+   assign i_in = clock ? i_in0 : i_in1;
+   assign q_in = clock ? q_in0 : q_in1;
+
+// This appears reversed because of the number of CORDIC stages
+   always @(posedge clock_2x)
+     if(clock)
+       begin
+	  bb_i1 <= #1 bb_i;
+	  bb_q1 <= #1 bb_q;
+       end
+     else
+       begin
+	  bb_i0 <= #1 bb_i;
+	  bb_q0 <= #1 bb_q;
+       end
+	
+   cordic rx_cordic
+     ( .clock(clock_2x),.reset(reset),.enable(enable), 
+       .xi(i_in),.yi(q_in),.zi(phase),
+       .xo(bb_i),.yo(bb_q),.zo() );
+   
+   cic_decim cic_decim_i_0
+     ( .clock(clock),.reset(reset),.enable(enable),
+       .rate(decim_rate),.strobe_in(sample_strobe),.strobe_out(decimator_strobe),
+       .signal_in(bb_i0),.signal_out(i_out0) );
+
+   cic_decim cic_decim_q_0
+     ( .clock(clock),.reset(reset),.enable(enable),
+       .rate(decim_rate),.strobe_in(sample_strobe),.strobe_out(decimator_strobe),
+       .signal_in(bb_q0),.signal_out(q_out0) );
+
+   cic_decim cic_decim_i_1
+     ( .clock(clock),.reset(reset),.enable(enable),
+       .rate(decim_rate),.strobe_in(sample_strobe),.strobe_out(decimator_strobe),
+       .signal_in(bb_i1),.signal_out(i_out1) );
+
+   cic_decim cic_decim_q_1
+     ( .clock(clock),.reset(reset),.enable(enable),
+       .rate(decim_rate),.strobe_in(sample_strobe),.strobe_out(decimator_strobe),
+       .signal_in(bb_q1),.signal_out(q_out1) );
+
+endmodule // rx_chain
-- 
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