////////////////////////////////////////////////////////////////////// //// //// //// File name: pci_target32_clk_en.v //// //// //// //// This file is part of the "PCI bridge" project //// //// http://www.opencores.org/cores/pci/ //// //// //// //// Author(s): //// //// - Tadej Markovic, tadej@opencores.org //// //// //// //// All additional information is avaliable in the README.txt //// //// file. //// //// //// //// //// ////////////////////////////////////////////////////////////////////// //// //// //// Copyright (C) 2000 Tadej Markovic, tadej@opencores.org //// //// //// //// This source file may be used and distributed without //// //// restriction provided that this copyright statement is not //// //// removed from the file and that any derivative work contains //// //// the original copyright notice and the associated disclaimer. //// //// //// //// This source file is free software; you can redistribute it //// //// and/or modify it under the terms of the GNU Lesser General //// //// Public License as published by the Free Software Foundation; //// //// either version 2.1 of the License, or (at your option) any //// //// later version. //// //// //// //// This source is distributed in the hope that it will be //// //// useful, but WITHOUT ANY WARRANTY; without even the implied //// //// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR //// //// PURPOSE. See the GNU Lesser General Public License for more //// //// details. //// //// //// //// You should have received a copy of the GNU Lesser General //// //// Public License along with this source; if not, download it //// //// from http://www.opencores.org/lgpl.shtml //// //// //// ////////////////////////////////////////////////////////////////////// // // CVS Revision History // // $Log: pci_target32_clk_en.v,v $ // Revision 1.1 2007-03-20 17:50:56 sithglan // add shit // // Revision 1.4 2003/01/27 16:49:31 mihad // Changed module and file names. Updated scripts accordingly. FIFO synchronizations changed. // // Revision 1.3 2002/02/01 15:25:12 mihad // Repaired a few bugs, updated specification, added test bench files and design document // // Revision 1.2 2001/10/05 08:14:30 mihad // Updated all files with inclusion of timescale file for simulation purposes. // // Revision 1.1.1.1 2001/10/02 15:33:47 mihad // New project directory structure // // // module is used to separate logic which uses criticaly constrained inputs from slower logic. // It is used to synthesize critical timing logic separately with faster cells or without optimization // synopsys translate_off `include "timescale.v" // synopsys translate_on module pci_target32_clk_en ( addr_phase, config_access, addr_claim_in, pci_frame_in, state_wait, state_transfere, state_default, clk_enable ); input addr_phase ; // indicates registered address phase on PCI bus input config_access ; // indicates configuration access input addr_claim_in ; // indicates claimed input PCI address input pci_frame_in ; // critical constrained input signal input state_wait ; // indicates WAIT state of FSM input state_transfere ; // indicates TRANSFERE state of FSM input state_default ; // indicates DEFAULT state of FSM output clk_enable ; // FSM clock enable output // clock enable signal when FSM is in IDLE state wire s_idle_clk_en = ((addr_phase && config_access) || (addr_phase && ~config_access && addr_claim_in)) ; // clock enable signal when FSM is in WAIT state or in DEFAULT state wire s_wait_clk_en = (state_wait || state_default) ; // clock enable signal when FSM is in TRANSFERE state wire s_tran_clk_en = (state_transfere && pci_frame_in) ; // Clock enable signal for FSM with preserved hierarchy for minimum delay! assign clk_enable = (s_idle_clk_en || s_wait_clk_en || s_tran_clk_en) ; endmodule