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//-----------------------------------------------------------------------------
// Project    : Virtex-6 Integrated Block for PCI Express
// File       : PIO_TO_CTRL.v
// Version    : 2.3
//--
//-- Description: Turn-off Control Unit.
//--
//--------------------------------------------------------------------------------

`timescale 1ns/1ns

module PIO_TO_CTRL    (

                        clk,
                        rst_n,

                        req_compl_i,
                        compl_done_i,

                        cfg_to_turnoff,
                        cfg_turnoff_ok

                        );

    input               clk;
    input               rst_n;

    input               req_compl_i;
    input               compl_done_i;

    input               cfg_to_turnoff;
    output              cfg_turnoff_ok;

    reg                 trn_pending;
    reg                 cfg_turnoff_ok;


   //  *  Check if completion is pending

    always @ ( posedge clk or negedge rst_n ) begin

        if (!rst_n ) begin

          trn_pending <= 0;

        end else begin

          if (!trn_pending && req_compl_i)

            trn_pending <= 1'b1;

          else if (compl_done_i)

            trn_pending <= 1'b0;

        end

    end

    // *  Turn-off OK if requested and no transaction is pending

     always @ ( posedge clk or negedge rst_n ) begin

      if (!rst_n ) begin

        cfg_turnoff_ok <= 1'b0;

      end else begin

        if ( cfg_to_turnoff  && !trn_pending)
          cfg_turnoff_ok <= 1'b1;
        else
          cfg_turnoff_ok <= 1'b0;

      end

    end


endmodule // PIO_TO_CTRL

