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//////////////////////////////////////////////////////////////////////

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//// hctxPortArbiter

////                                                              ////

//// This file is part of the usbhostslave opencores effort.

//// http://www.opencores.org/cores/usbhostslave/                 ////

////                                                              ////

//// Module Description:                                          ////

//// 

////                                                              ////

//// To Do:                                                       ////

//// 

////                                                              ////

//// Author(s):                                                   ////

//// - Steve Fielding, sfielding@base2designs.com                 ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

////                                                              ////

//// Copyright (C) 2004 Steve Fielding and 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                     ////

////                                                              ////

//////////////////////////////////////////////////////////////////////

//

// $Id: hctxportarbiter.v,v 1.2 2004-12-18 14:36:09 sfielding Exp $

//

// CVS Revision History

//

// $Log: not supported by cvs2svn $

//

`timescale 1ns / 1ps

module HCTxPortArbiter (clk, directCntlCntl, directCntlData, directCntlGnt, directCntlReq, directCntlWEn, HCTxPortCntl, HCTxPortData, HCTxPortWEnable, rst, sendPacketCntl, sendPacketData, sendPacketGnt, sendPacketReq, sendPacketWEn, SOFCntlCntl, SOFCntlData, SOFCntlGnt, SOFCntlReq, SOFCntlWEn);

input   clk;

input   [7:0]directCntlCntl;

input   [7:0]directCntlData;

input   directCntlReq;

input   directCntlWEn;

input   rst;

input   [7:0]sendPacketCntl;

input   [7:0]sendPacketData;

input   sendPacketReq;

input   sendPacketWEn;

input   [7:0]SOFCntlCntl;

input   [7:0]SOFCntlData;

input   SOFCntlReq;

input   SOFCntlWEn;

output  directCntlGnt;

output  [7:0]HCTxPortCntl;

output  [7:0]HCTxPortData;

output  HCTxPortWEnable;

output  sendPacketGnt;

output  SOFCntlGnt;

wire    clk;

wire    [7:0]directCntlCntl;

wire    [7:0]directCntlData;

reg     directCntlGnt, next_directCntlGnt;

wire    directCntlReq;

wire    directCntlWEn;

reg     [7:0]HCTxPortCntl, next_HCTxPortCntl;

reg     [7:0]HCTxPortData, next_HCTxPortData;

reg     HCTxPortWEnable, next_HCTxPortWEnable;

wire    rst;

wire    [7:0]sendPacketCntl;

wire    [7:0]sendPacketData;

reg     sendPacketGnt, next_sendPacketGnt;

wire    sendPacketReq;

wire    sendPacketWEn;

wire    [7:0]SOFCntlCntl;

wire    [7:0]SOFCntlData;

reg     SOFCntlGnt, next_SOFCntlGnt;

wire    SOFCntlReq;

wire    SOFCntlWEn;

// Constants

`define DIRECT_CTRL_MUX 2'b10

`define SEND_PACKET_MUX 2'b00

`define SOF_CTRL_MUX 2'b01

// diagram signals declarations

reg  [1:0]muxCntl, next_muxCntl;

// BINARY ENCODED state machine: HCTxArb

// State codes definitions:

`define START_HARB 3'b000

`define WAIT_REQ 3'b001

`define SEND_SOF 3'b010

`define SEND_PACKET 3'b011

`define DIRECT_CONTROL 3'b100

reg [2:0]CurrState_HCTxArb, NextState_HCTxArb;

// Diagram actions (continuous assignments allowed only: assign ...)

// SOFController/directContol/sendPacket mux

always @(muxCntl or SOFCntlWEn or SOFCntlData or SOFCntlCntl or

directCntlWEn or directCntlData or directCntlCntl or

directCntlWEn or directCntlData or directCntlCntl or

sendPacketWEn or sendPacketData or sendPacketCntl)

begin

case (muxCntl)

`SOF_CTRL_MUX :

begin

HCTxPortWEnable <= SOFCntlWEn;

HCTxPortData <= SOFCntlData;

HCTxPortCntl <= SOFCntlCntl;

end

`DIRECT_CTRL_MUX :

begin

HCTxPortWEnable <= directCntlWEn;

HCTxPortData <= directCntlData;

HCTxPortCntl <= directCntlCntl;

end

`SEND_PACKET_MUX :

begin

HCTxPortWEnable <= sendPacketWEn;

HCTxPortData <= sendPacketData;

HCTxPortCntl <= sendPacketCntl;

end

default :

begin

HCTxPortWEnable <= 1'b0;

HCTxPortData <= 8'h00;

HCTxPortCntl <= 8'h00;

end

endcase

end

// Machine: HCTxArb

// NextState logic (combinatorial)

always @ (SOFCntlReq or sendPacketReq or directCntlReq or SOFCntlGnt or sendPacketGnt or directCntlGnt or muxCntl or CurrState_HCTxArb)

begin

  NextState_HCTxArb = CurrState_HCTxArb;

  // Set default values for outputs and signals

  next_SOFCntlGnt <= SOFCntlGnt;

  next_sendPacketGnt <= sendPacketGnt;

  next_directCntlGnt <= directCntlGnt;

  next_muxCntl <= muxCntl;

  case (CurrState_HCTxArb)  // synopsys parallel_case full_case

    `START_HARB:

    begin

      NextState_HCTxArb = `WAIT_REQ;

    end

    `WAIT_REQ:

    begin

      if (SOFCntlReq == 1'b1)

      begin

        NextState_HCTxArb = `SEND_SOF;

        next_SOFCntlGnt <= 1'b1;

        next_muxCntl <= `SOF_CTRL_MUX;

      end

      else if (sendPacketReq == 1'b1)

      begin

        NextState_HCTxArb = `SEND_PACKET;

        next_sendPacketGnt <= 1'b1;

        next_muxCntl <= `SEND_PACKET_MUX;

      end

      else if (directCntlReq == 1'b1)

      begin

        NextState_HCTxArb = `DIRECT_CONTROL;

        next_directCntlGnt <= 1'b1;

        next_muxCntl <= `DIRECT_CTRL_MUX;

      end

    end

    `SEND_SOF:

    begin

      if (SOFCntlReq == 1'b0)

      begin

        NextState_HCTxArb = `WAIT_REQ;

        next_SOFCntlGnt <= 1'b0;

      end

    end

    `SEND_PACKET:

    begin

      if (sendPacketReq == 1'b0)

      begin

        NextState_HCTxArb = `WAIT_REQ;

        next_sendPacketGnt <= 1'b0;

      end

    end

    `DIRECT_CONTROL:

    begin

      if (directCntlReq == 1'b0)

      begin

        NextState_HCTxArb = `WAIT_REQ;

        next_directCntlGnt <= 1'b0;

      end

    end

  endcase

end

// Current State Logic (sequential)

always @ (posedge clk)

begin

  if (rst)

    CurrState_HCTxArb = `START_HARB;

  else

    CurrState_HCTxArb = NextState_HCTxArb;

end

// Registered outputs logic

always @ (posedge clk)

begin

  if (rst)

  begin

    SOFCntlGnt = 1'b0;

    sendPacketGnt = 1'b0;

    directCntlGnt = 1'b0;

    muxCntl = 2'b00;

  end

  else

  begin

    SOFCntlGnt = next_SOFCntlGnt;

    sendPacketGnt = next_sendPacketGnt;

    directCntlGnt = next_directCntlGnt;

    muxCntl = next_muxCntl;

  end

end

endmodule