Subversion Repositories sbd_sqrt_fp

/****************************************************************************

sbd_shifter_left2

- shift register - shifts left - towards MSB - 2 bits

Copyright (C) 2005 Samuel Brown

sam.brown@sbdesign.org

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 of the License, or (at your option) any later version.

This library 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

Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public

License along with this library; if not, write to the Free Software

Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

****************************************************************************/

module sbd_shifter_left2 (SIN,PIN,LOAD,RST,SHIFT,CLK,SOUT,POUT);

parameter bitlength = 24;

input [1:0] SIN;

input [bitlength-1:0] PIN;

input LOAD;

input RST;

input SHIFT;

input CLK;

output wire [1:0] SOUT;

output wire [bitlength-1:0] POUT;

reg  [bitlength-1:0] writeData, readData;

assign POUT = readData;

assign SOUT = readData[bitlength-1:bitlength-2];

always @ (posedge CLK)

begin:shiftreg

   if(RST) readData <= 0;

   else if(SHIFT | LOAD) readData <= writeData;

end

always @ (readData, SIN, PIN, LOAD)

begin:shiftmux

   if(LOAD) writeData = PIN;

   else writeData = { readData[bitlength-3:0], SIN };

end

endmodule