prog_mem.v

嵌入式操作系统的基本输入输出程序

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////  Mini-RISC-1                                                ////
////  Program Memory                                             ////
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////  Author: Rudolf Usselmann                                   ////
////          [e-mail]                                      ////
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////  D/L from: http://www.opencores.org/cores/minirisc/         ////
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//// Copyright (C) 2000-2002 Rudolf Usselmann                    ////
////                         www.asics.ws                        ////
////                         [e-mail]                       ////
////                                                             ////
//// 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 SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     ////
//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   ////
//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   ////
//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      ////
//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,         ////
//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES    ////
//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE   ////
//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR        ////
//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF  ////
//// LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT  ////
//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT  ////
//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE         ////
//// POSSIBILITY OF SUCH DAMAGE.                                 ////
////                                                             ////
/////////////////////////////////////////////////////////////////////

//  CVS Log
//
//  $Id: prog_mem.v,v 1.2 2002/09/27 15:35:41 rudi Exp $
//
//  $Date: 2002/09/27 15:35:41 $
//  $Revision: 1.2 $
//  $Author: rudi $
//  $Locker:  $
//  $State: Exp $
//
// Change History:
//               $Log: prog_mem.v,v $
//               Revision 1.2  2002/09/27 15:35:41  rudi
//               Minor update to newer devices ...
//
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`timescale 1ns / 10ps

// For simulation only
// May be off or on chip

module prog_mem ( clk, address, we, din, dout );

input		clk;
input [10:0]	address;
input		we;
input [11:0]	din;
output [11:0]	dout;

parameter depth = 2048;

reg [10:0]	addr_r;
reg [11:0]	mem[0:depth-1];

always @(posedge clk)
   addr_r <= address;
   
assign dout = mem[addr_r];

always @(posedge clk)
   if (we) mem[address] <= din;

endmodule