Subversion Repositories openrisc_2011-10-31

//////////////////////////////////////////////////////////////////////
////                                                              ////
//// dpMem_dc.v                                                 ////
////                                                              ////
//// This file is part of the usbhostslave opencores effort.
//// <http://www.opencores.org/cores//>                           ////
////                                                              ////
//// Module Description:                                          ////
//// Synchronous dual port memory with dual clocks
////                                                              ////
//// 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 dpMem_dc(  addrIn, addrOut, wrClk, rdClk, dataIn, writeEn, readEn, dataOut);
   //FIFO_DEPTH = ADDR_WIDTH^2
   parameter FIFO_WIDTH = 8;
   parameter FIFO_DEPTH = 64; 
   parameter ADDR_WIDTH = 6;   
 
   input wrClk;
   input rdClk;
   input [FIFO_WIDTH-1:0] dataIn;
   output [FIFO_WIDTH-1:0] dataOut;
   input 		   writeEn;
   input 		   readEn;
   input [ADDR_WIDTH-1:0]  addrIn;
   input [ADDR_WIDTH-1:0]  addrOut;
 
   wire 		   wrClk;
   wire 		   rdClk;
   wire [FIFO_WIDTH-1:0]   dataIn;
   //reg [FIFO_WIDTH-1:0] dataOut;
   wire [FIFO_WIDTH-1:0]   dataOut;
   wire 		   writeEn;
   wire 		   readEn;
   wire [ADDR_WIDTH-1:0]   addrIn;
   wire [ADDR_WIDTH-1:0]   addrOut;
 
   // Added no_rw_check on this -- Julius
   reg [FIFO_WIDTH-1:0]    buffer [0:FIFO_DEPTH-1] /*synthesis syn_ramstyle = "no_rw_check"*/;
 
   // Modifying this to ensure this is inferred as a block RAM
 
   // Register address
   reg [ADDR_WIDTH-1:0]    addrOut_r;
 
   always @(posedge rdClk)
     //not sure if we should have this enable here:
     // if (readEn)
     addrOut_r <= addrOut;
 
   assign dataOut = buffer[addrOut_r];
 
   // synchronous write
   always @(posedge wrClk) begin
      if (writeEn == 1'b1)
	buffer[addrIn] <= dataIn;
   end                  
 
/*   
   // synchronous read. Introduces one clock cycle delay
 
   always @(posedge rdClk) begin
      dataOut <= buffer[addrOut];
   end
 
 
   // synchronous write
   always @(posedge wrClk) begin
      if (writeEn == 1'b1)
	buffer[addrIn] <= dataIn;
   end                  
*/
 
endmodule