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//nophandler_l3.h

/* ***** BEGIN LICENSE BLOCK *****

 * Version: MPL 1.1

 *

 * The contents of this file are subject to the Mozilla Public License Version

 * 1.1 (the "License"); you may not use this file except in compliance with

 * the License. You may obtain a copy of the License at

 * http://www.mozilla.org/MPL/

 *

 * Software distributed under the License is distributed on an "AS IS" basis,

 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License

 * for the specific language governing rights and limitations under the

 * License.

 *

 * The Original Code is HyperTransport Tunnel IP Core.

 *

 * The Initial Developer of the Original Code is

 * Ecole Polytechnique de Montreal.

 * Portions created by the Initial Developer are Copyright (C) 2005

 * the Initial Developer. All Rights Reserved.

 *

 * Contributor(s):

 *   Ami Castonguay <acastong@grm.polymtl.ca>

 *   Laurent Aubray

 *

 * Alternatively, the contents of this file may be used under the terms

 * of the Polytechnique HyperTransport Tunnel IP Core Source Code License

 * (the  "PHTICSCL License", see the file PHTICSCL.txt), in which case the

 * provisions of PHTICSCL License are applicable instead of those

 * above. If you wish to allow use of your version of this file only

 * under the terms of the PHTICSCL License and not to allow others to use

 * your version of this file under the MPL, indicate your decision by

 * deleting the provisions above and replace them with the notice and

 * other provisions required by the PHTICSCL License. If you do not delete

 * the provisions above, a recipient may use your version of this file

 * under either the MPL or the PHTICSCL License."

 *

 * ***** END LICENSE BLOCK ***** */

#ifndef NOPHANDLER_L2_H

#define NOPHANDLER_L2_H

#include "../core_synth/synth_datatypes.h"

#include "../core_synth/constants.h"

///Keeps track of buffer count and requesting that nops are sent

/**

        The nophandler takes care of tracking the number of buffers that

        are used.  It also keeps track of how many buffers the next HT

        node think we have.  When necessary, it makes a request to the

        flow control to send a nop to readjust the difference in count.

*/

class nophandler_l3: public sc_module

{

public:

        //***********************************

        // Ports definition

        //***********************************

        /// The Clock

        sc_in<bool> clk;

        /// Reset signal

        sc_in<bool> resetx;

        //When the flow control sent a nop with buffer information

        sc_in<bool> fc_nop_sent;

        //To notify that packets have been received, one signal per VC

        sc_in<bool> received_packet[3];

        //To notify that packets have been sent and the buffer is free, one signal per VC

        //2 bit vector (one for cleared accepted and one for forward).  If the same packet

        //was sent to both accepted and forward, only one of the bits will be asserted

        sc_in<sc_bv<2> > buffers_cleared[3];

        //To request that a nop be sent

        sc_out<bool> ro_nop_req_fc;

        //The buffer count to send on the nop

        sc_out<sc_bv<6> > ro_buffer_cnt_fc;

#ifdef RETRY_MODE_ENABLED

        ///RX link is not connected

        sc_in< bool >                                                           lk_rx_connected;

        ///If the retry mode is active

        sc_in< bool >                                                           csr_retry;

        ///Let the CSR know we received a non flow control stomped packet

        sc_in<bool> cd_received_non_flow_stomped_ro;

        ///Virtual Channel of input VC, only used to clear buffer credit of stomped packet

        sc_in<VirtualChannel> input_packet_vc;

#endif

        //Count of the number of buffers that are advertised as being free to the next node

        sc_signal<sc_uint<LOG2_NB_OF_BUFFERS + 1> > bufferCount[3];

        //The number of free buffers

        sc_signal<sc_uint<LOG2_NB_OF_BUFFERS + 1> > freeBuffers[3];

        //If a nop has already been requested

        sc_signal<bool> nopRequested;

        ///All registered signals and outputs are treated here

        void clockedProcess();

        ///Get the number of buffers freed in that VC

        sc_uint<2> getBufferFreedNop(const VirtualChannel vc);

        ///Outputs the nop request with the correct ro_buffer_cnt_fc value

        void outputNopRequest(

                const sc_uint<LOG2_NB_OF_BUFFERS + 1> buffersThatCanBeFreedWithNop_2,

                const sc_uint<LOG2_NB_OF_BUFFERS + 1> buffersThatCanBeFreedWithNop_1,

                const sc_uint<LOG2_NB_OF_BUFFERS + 1> buffersThatCanBeFreedWithNop_0);

        ///SystemC module macro

        SC_HAS_PROCESS(nophandler_l3);

        /// Constructor of the nophandler_l3 module

        /**

                @param name Name of the module

        */

        nophandler_l3( sc_module_name name);

#ifdef SYSTEMC_SIM

        /// Destructor

        virtual ~nophandler_l3(){}

#endif

};

#endif