///////////////////////////////////////////
// clockgater.sv
//
// Written: Ross Thompson 9 January 2021
// Modified: 
//
// Purpose: Clock gater model. Must use standard cell for synthesis.
// 
// A component of the Wally configurable RISC-V project.
// 
// Copyright (C) 2021 Harvey Mudd College & Oklahoma State University
//
// Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation
// files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, 
// modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software 
// is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 
// BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT 
// OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
///////////////////////////////////////////

`include "wally-config.vh"

module clockgater
  (input logic 	E,
   input logic 	SE,
   input logic 	CLK,
   output logic ECLK);

  // VERY IMPORTANT.
  // This part functionally models a clock gater, but does not necessarily meet the timing constrains a real standard cell would.
  // Do not use this in synthesis!

  logic 	enable_q;
  

  always_latch begin
    if(~CLK) begin
      enable_q <= E | SE;
    end
  end
  assign ECLK = enable_q & CLK;

endmodule