Subversion Repositories pcie_sg_dma

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

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

// Project    : Virtex-6 Integrated Block for PCI Express

// File       : PIO_TO_CTRL.v

// Version    : 1.7

//--

//-- Description: Turn-off Control Unit.

//--

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

`timescale 1ns/1ns

module PIO_TO_CTRL    (

                        clk,

                        rst_n,

                        req_compl_i,

                        compl_done_i,

                        cfg_to_turnoff_n,

                        cfg_turnoff_ok_n

                        );

    input               clk;

    input               rst_n;

    input               req_compl_i;

    input               compl_done_i;

    input               cfg_to_turnoff_n;

    output              cfg_turnoff_ok_n;

    reg                 trn_pending;

    reg                 cfg_turnoff_ok_n;

    // *  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_n <= 1'b1;

      end else begin

        if ( !cfg_to_turnoff_n  && !trn_pending)

          cfg_turnoff_ok_n <= 1'b0;

        else

          cfg_turnoff_ok_n <= 1'b1;

      end

    end

endmodule // PIO_TO_CTRL