Subversion Repositories openmsp430

//----------------------------------------------------------------------------

// Copyright (C) 2009 , Olivier Girard

//

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions

// are met:

//     * Redistributions of source code must retain the above copyright

//       notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above copyright

//       notice, this list of conditions and the following disclaimer in the

//       documentation and/or other materials provided with the distribution.

//     * Neither the name of the authors nor the names of its contributors

//       may be used to endorse or promote products derived from this software

//       without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"

// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE

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// OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

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//

//----------------------------------------------------------------------------

//

// *File Name: omsp_and_gate.v

// 

// *Module Description:

//                       Generic AND gate cell for the openMSP430

//

// *Author(s):

//              - Olivier Girard,    olgirard@gmail.com

//

//----------------------------------------------------------------------------

// $Rev: 103 $

// $LastChangedBy: olivier.girard $

// $LastChangedDate: 2011-03-05 15:44:48 +0100 (Sat, 05 Mar 2011) $

//----------------------------------------------------------------------------

module  omsp_and_gate (

// OUTPUTs

    y,                         // AND gate output

// INPUTs

    a,                         // AND gate input A

    b                          // AND gate input B

);

// OUTPUTs

//=========

output         y;              // AND gate output

// INPUTs

//=========

input          a;              // AND gate input A

input          b;              // AND gate input B

//=============================================================================

// 1)  SOME COMMENTS ON THIS MODULE

//=============================================================================

//

//    In its ASIC version, some combinatorial pathes of the openMSP430 are

// sensitive to glitches, in particular the ones generating the wakeup

// signals.

//    To prevent synthesis from optmizing combinatorial clouds into glitchy

// logic, this AND gate module has been instanciated in the critical places.

//

//    Make sure that synthesis doesn't ungroup this module. As an alternative,

// a standard cell from the library could also be directly instanciated here

// (don't forget the "dont_touch" attribute)

//

//

//=============================================================================

// 2)  AND GATE

//=============================================================================

assign  y  =  a & b;

endmodule // omsp_and_gate