Subversion Repositories openrisc

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

////                                                              ////

//// RxFifo.v                                                     ////

////                                                              ////

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

//// <http://www.opencores.org/cores//>                           ////

////                                                              ////

//// Module Description:                                          ////

////  parameterized RxFifo wrapper. Min depth = 2, Max depth = 65536

////  fifo read access via bus interface, fifo write access is direct

//// 

////                                                              ////

//// 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>                   ////

////                                                              ////

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

//

`include "timescale.v"

module RxFifo(

  busClk,

  usbClk,

  rstSyncToBusClk,

  rstSyncToUsbClk,

  fifoWEn,

  fifoFull,

  busAddress,

  busWriteEn,

  busStrobe_i,

  busFifoSelect,

  busDataIn,

  busDataOut,

  fifoDataIn  );

  //FIFO_DEPTH = ADDR_WIDTH^2

  parameter FIFO_DEPTH = 64;

  parameter ADDR_WIDTH = 6;

input busClk;

input usbClk;

input rstSyncToBusClk;

input rstSyncToUsbClk;

input fifoWEn;

output fifoFull;

input [2:0] busAddress;

input busWriteEn;

input busStrobe_i;

input busFifoSelect;

input [7:0] busDataIn;

output [7:0] busDataOut;

input [7:0] fifoDataIn;

wire busClk;

wire usbClk;

wire rstSyncToBusClk;

wire rstSyncToUsbClk;

wire fifoWEn;

wire fifoFull;

wire [2:0] busAddress;

wire busWriteEn;

wire busStrobe_i;

wire busFifoSelect;

wire [7:0] busDataIn;

wire [7:0] busDataOut;

wire [7:0] fifoDataIn;

//internal wires and regs

wire [7:0] dataFromFifoToBus;

wire fifoREn;

wire forceEmptySyncToBusClk;

wire forceEmptySyncToUsbClk;

wire [15:0] numElementsInFifo;

wire fifoEmpty;   //not used

fifoRTL #(8, FIFO_DEPTH, ADDR_WIDTH) u_fifo(

  .wrClk(usbClk),

  .rdClk(busClk),

  .rstSyncToWrClk(rstSyncToUsbClk),

  .rstSyncToRdClk(rstSyncToBusClk),

  .dataIn(fifoDataIn),

  .dataOut(dataFromFifoToBus),

  .fifoWEn(fifoWEn),

  .fifoREn(fifoREn),

  .fifoFull(fifoFull),

  .fifoEmpty(fifoEmpty),

  .forceEmptySyncToWrClk(forceEmptySyncToUsbClk),

  .forceEmptySyncToRdClk(forceEmptySyncToBusClk),

  .numElementsInFifo(numElementsInFifo) );

RxfifoBI u_RxfifoBI(

  .address(busAddress),

  .writeEn(busWriteEn),

  .strobe_i(busStrobe_i),

  .busClk(busClk),

  .usbClk(usbClk),

  .rstSyncToBusClk(rstSyncToBusClk),

  .fifoSelect(busFifoSelect),

  .fifoDataIn(dataFromFifoToBus),

  .busDataIn(busDataIn),

  .busDataOut(busDataOut),

  .fifoREn(fifoREn),

  .forceEmptySyncToBusClk(forceEmptySyncToBusClk),

  .forceEmptySyncToUsbClk(forceEmptySyncToUsbClk),

  .numElementsInFifo(numElementsInFifo)

  );

endmodule