Houston, we have a trunk.

git-svn-id: http://gnuradio.org/svn/gnuradio/trunk@3122 221aa14e-8319-0410-a670-987f0aec2ac5

1 files changed, 106 insertions, 0 deletions

diff --git a/toplevel/mrfm/shifter.v b/toplevel/mrfm/shifter.v
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+// -*- verilog -*-
+//
+//  USRP - Universal Software Radio Peripheral
+//
+//  Copyright (C) 2005,2006 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+
+module shifter(input wire [33:0] in, output wire [15:0] out, input wire [7:0] shift);
+   // Wish we could do  assign out = in[15+shift:shift];
+
+   reg [15:0] quotient, remainder;
+   wire [15:0] out_unclipped;
+   reg [18:0]  msbs;
+   wire        in_range;
+   
+   always @*
+     case(shift)
+       0 : quotient = in[15:0];
+       1 : quotient = in[16:1];
+       2 : quotient = in[17:2];
+       3 : quotient = in[18:3];
+       4 : quotient = in[19:4];
+       5 : quotient = in[20:5];
+       6 : quotient = in[21:6];
+       7 : quotient = in[22:7];
+       8 : quotient = in[23:8];
+       9 : quotient = in[24:9];
+       10 : quotient = in[25:10];
+       11 : quotient = in[26:11];
+       12 : quotient = in[27:12];
+       13 : quotient = in[28:13];
+       14 : quotient = in[29:14];
+       15 : quotient = in[30:15];
+       16 : quotient = in[31:16];
+       17 : quotient = in[32:17];
+       18 : quotient = in[33:18];
+       default : quotient = in[15:0];
+     endcase // case(shift)
+
+   always @*
+     case(shift)
+       0 : remainder = 16'b0;
+       1 : remainder = {in[0],15'b0};
+       2 : remainder = {in[1:0],14'b0};
+       3 : remainder = {in[2:0],13'b0};
+       4 : remainder = {in[3:0],12'b0};
+       5 : remainder = {in[4:0],11'b0};
+       6 : remainder = {in[5:0],10'b0};
+       7 : remainder = {in[6:0],9'b0};
+       8 : remainder = {in[7:0],8'b0};
+       9 : remainder = {in[8:0],7'b0};
+       10 : remainder = {in[9:0],6'b0};
+       11 : remainder = {in[10:0],5'b0};
+       12 : remainder = {in[11:0],4'b0};
+       13 : remainder = {in[12:0],3'b0};
+       14 : remainder = {in[13:0],2'b0};
+       15 : remainder = {in[14:0],1'b0};
+       16 : remainder = in[15:0];
+       17 : remainder = in[16:1];
+       18 : remainder = in[17:2];
+       default : remainder = 16'b0;
+     endcase // case(shift)
+
+   always @*
+     case(shift)
+       0 : msbs = in[33:15];
+       1 : msbs = {in[33],in[33:16]};
+       2 : msbs = {{2{in[33]}},in[33:17]};
+       3 : msbs = {{3{in[33]}},in[33:18]};
+       4 : msbs = {{4{in[33]}},in[33:19]};
+       5 : msbs = {{5{in[33]}},in[33:20]};
+       6 : msbs = {{6{in[33]}},in[33:21]};
+       7 : msbs = {{7{in[33]}},in[33:22]};
+       8 : msbs = {{8{in[33]}},in[33:23]};
+       9 : msbs = {{9{in[33]}},in[33:24]};
+       10 : msbs = {{10{in[33]}},in[33:25]};
+       11 : msbs = {{11{in[33]}},in[33:26]};
+       12 : msbs = {{12{in[33]}},in[33:27]};
+       13 : msbs = {{13{in[33]}},in[33:28]};
+       14 : msbs = {{14{in[33]}},in[33:29]};
+       15 : msbs = {{15{in[33]}},in[33:30]};
+       16 : msbs = {{16{in[33]}},in[33:31]};
+       17 : msbs = {{17{in[33]}},in[33:32]};
+       18 : msbs = {{18{in[33]}},in[33]};
+       default : msbs = in[33:15];
+     endcase // case(shift)
+
+   assign     in_range = &msbs | ~(|msbs);
+   assign     out_unclipped = quotient + (in[33] & |remainder);
+   assign     out = in_range ? out_unclipped : {in[33],{15{~in[33]}}};
+   
+endmodule // shifter