3 // USRP - Universal Software Radio Peripheral
5 // Copyright (C) 2003 Matt Ettus
7 // This program is free software; you can redistribute it and/or modify
8 // it under the terms of the GNU General Public License as published by
9 // the Free Software Foundation; either version 2 of the License, or
10 // (at your option) any later version.
12 // This program is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 51 Franklin Street, Boston, MA 02110-1301 USA
22 module cordic_stage( clock, reset, enable, xi,yi,zi,constant,xo,yo,zo);
23 parameter bitwidth = 16;
24 parameter zwidth = 16;
30 input [bitwidth-1:0] xi,yi;
31 input [zwidth-1:0] zi;
32 input [zwidth-1:0] constant;
33 output [bitwidth-1:0] xo,yo;
34 output [zwidth-1:0] zo;
36 wire z_is_pos = ~zi[zwidth-1];
38 reg [bitwidth-1:0] xo,yo;
41 always @(posedge clock)
51 xi - {{shift+1{yi[bitwidth-1]}},yi[bitwidth-2:shift]} :
52 xi + {{shift+1{yi[bitwidth-1]}},yi[bitwidth-2:shift]};
54 yi + {{shift+1{xi[bitwidth-1]}},xi[bitwidth-2:shift]} :
55 yi - {{shift+1{xi[bitwidth-1]}},xi[bitwidth-2:shift]};