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