Merged r5463:5504 from jcorgan/snd into trunk. Work in progress, adds digital loopbac...

[debian/gnuradio] / gr-sounder / src / fpga / lib / strobe.v

diff --git a/gr-sounder/src/fpga/lib/strobe.v b/gr-sounder/src/fpga/lib/strobe.v
new file mode 100644 (file)
index 0000000..ed07f21
--- /dev/null
+++ b/gr-sounder/src/fpga/lib/strobe.v
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+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2007 Corgan Enterprises LLC
+//
+//  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 strobe(clk_i,rst_i,ena_i,rate_i,strobe_i,strobe_o,count_o);
+   parameter width = 16;
+
+   input              clk_i;
+   input             rst_i;
+   input             ena_i;
+   input  [width-1:0] rate_i;  // Desired period minus one
+   input             strobe_i;
+   output            strobe_o;
+   output [width-1:0] count_o;
+
+   
+   reg [width-1:0] counter;
+
+   always @(posedge clk_i)
+     if(rst_i | ~ena_i)
+       counter <= 32'hFFFFFFFF;        // First period is short by one
+     else if(strobe_i)
+       if(counter == rate_i)
+        counter <= 0;
+       else 
+        counter <= counter + 1;
+
+   assign strobe_o = (counter == rate_i) & strobe_i;
+   assign count_o = counter;
+   
+endmodule // strobe