m3s016bo.v

another 8051 core porocesssor vhdl source code

//*******************************************************************       //
//IMPORTANT NOTICE                                                          //
//================                                                          //
//Copyright Mentor Graphics Corporation 1996 - 1999.  All rights reserved.  //
//This file and associated deliverables are the trade secrets,              //
//confidential information and copyrighted works of Mentor Graphics         //
//Corporation and its licensors and are subject to your license agreement   //
//with Mentor Graphics Corporation.                                         //
//                                                                          //
//Use of these deliverables for the purpose of making silicon from an IC    //
//design is limited to the terms and conditions of your license agreement   //
//with Mentor Graphics If you have further questions please contact Mentor  //
//Graphics Customer Support.                                                //
//                                                                          //
//This Mentor Graphics core (m8051 v1999.120) was extracted on              //
//workstation hostid _hostid_ Inventra                                      //
//8-bit up counter for M8051
//Copyright Mentor Graphics Corporation and Licensors 1998. All Rights Reserved.
//v2.001
////////////////////////////////////////////////////////////////////////////////
//
// Verilog file generated by X-HDL - Revision 3.0_11 Beta C April 24, 1998
// Thu Jul  9 22:05:25 1998
//
// Input file : m3s016bo.vhd
// Design name : m3s016bo
// Author : 
// Company : Mentor Graphics - Inventra
//
// Description : 
//
//
////////////////////////////////////////////////////////////////////////////////
//
//*********************************************************************
//%W% %G% SCCS Version Control
//File	        :       m3s016bo.vhd
//Created on    :       8th April 1997
//Purpose       :       8-bit up counter for M8051
//Version       :       2.001
//Mod Date      :       2nd April 1998
//Mod History	:       2.001 _e suffix removed from entity names.
//
//*********************************************************************
//Hierarchy record      :
//Called by             :m3s015bo.vhd
//                      :
//Calls to              :
//*********************************************************************
//*********************************************************************
//Entity Definition
//*********************************************************************
module m3s016bo (CO, CNT, MODE0, LD, CI, CLEAR, COUNT_EN, NX1, DIN);
//*******************************************************************       //
//IMPORTANT NOTICE                                                          //
//================                                                          //
//Copyright Mentor Graphics Corporation 1996 - 1999.  All rights reserved.  //
//This file and associated deliverables are the trade secrets,              //
//confidential information and copyrighted works of Mentor Graphics         //
//Corporation and its licensors and are subject to your license agreement   //
//with Mentor Graphics Corporation.                                         //
//                                                                          //
//Use of these deliverables for the purpose of making silicon from an IC    //
//design is limited to the terms and conditions of your license agreement   //
//with Mentor Graphics If you have further questions please contact Mentor  //
//Graphics Customer Support.                                                //
//                                                                          //
//This Mentor Graphics core (m8051 v1999.120) was extracted on              //
//workstation hostid _hostid_ Inventra                                      //

  output CO;
  reg CO;
  output[7:0] CNT;
  reg[7:0] CNT;
  input MODE0;
  input LD;
  input CI;
  input CLEAR;
  input COUNT_EN;
  input NX1;
  input[7:0] DIN;

  //*********************************************************************
  //signal definition
  //*********************************************************************
  reg[7:0] LCT; 
  reg C4; 

  always @(posedge NX1)
  begin : set_count
    if (CLEAR)
    begin
      LCT <= 8'b00000000 ; 
    end
    else if (COUNT_EN)
    begin
      if (LD)
      begin
        LCT <= DIN ; 
      end
      else
      begin
        LCT[0] <= LCT[0] ^ CI ; 
        LCT[1] <= LCT[1] ^ (CI & LCT[0]) ; 
        LCT[2] <= LCT[2] ^ (CI & LCT[0] & LCT[1]) ; 
        LCT[3] <= LCT[3] ^ (CI & LCT[0] & LCT[1] & LCT[2]) ; 
        LCT[4] <= LCT[4] ^ C4 ; 
        LCT[5] <= LCT[5] ^ (C4 & LCT[4]) ; 
        LCT[6] <= LCT[6] ^ (C4 & LCT[4] & LCT[5]) ; 
        LCT[7] <= LCT[7] ^ (C4 & LCT[4] & LCT[5] & LCT[6]) ; 
      end 
    end  
  end 

  always @(LCT or CI or MODE0)
  begin : set_carry
    // Generate counter carry out for five or eight bit modes with
    // combinatorial dependence on the counter carry input.
    // Map local variable to global name for export.
    C4 <= CI & LCT[0] & LCT[1] & LCT[2] & LCT[3] ; 
    CO <= CI & LCT[0] & LCT[1] & LCT[2] & LCT[3] & LCT[4] & (MODE0 | (LCT[
    5] & LCT[6] & LCT[7])) ; 
    CNT <= LCT ; 
  end 
  //*********************************************************************
endmodule