/****************************************************/
      /*         Release Notes for Version 6.12           */
      /*           8051 DEVELOPMENT TOOL KITS             */
      /****************************************************/

This file contains release notes and last minute changes relating
to the 8051 Version 6.12 Tool Chain. Information in this file, the 
accompanying manual, and software is Copyright (c) 2001 Keil 
Software and Keil Elektronik. All rights reserved.


Contents
========

1.  What's New in C51 Version 6.12

2.  uVision2 Integrated Development Environment

3.  Compiler Enhancements

4.  Assembler Enhancements

5.  Linker Enhancements

6.  Manuals Provided

7.  Example Programs

8.  New Devices & Register Header Files

9.  uVision2 Debugger - On Chip Peripherals in the Simulator

10. Sales and Technical Support


1.  What's New in C51 Version 6.12

    There are numerous new features in C51 that make your software
    development efforts easier.

    - 32-bit applications run in Windows 95/98/NT/2000/ME.

    - Long filenames are supported.

    - New optimizer levels shrink program code size.

    - The uVision2 IDE is enhanced to make software development
      faster and easier.

    - The Device Database makes CPU configuration a one-click process.
      All assembler, compiler, and linker options are set automatically.

    - The Source Browser allows you to quickly navigate your program's
      variables and functions.

    We are constantly improving our products. To keep your product 
    current during the Support Period listed in the uVision2 
    "About" box, download the latest updates from our Web page. If
    your support is exhausted, contact our Sales department to 
    extend your support period.

    Compared to Version 6.00, Release V6.12 contains the following
    enhancements:

    - C51 directives RET_PSTK, and RET_XSTK unload the on-chip stack 
      and use the reentrant stack for storing the return address.

    - The ANSI library functions modf, strtod, strtol, and strtoul
      have been added.

    - Linker directives have been enhanced to support multiple XDATA
      and CODE address ranges.

    - Wildcards are now supported in the segment control directives.

    - Simulation support has been added for the on-chip peripherals of
      the Analog Devices ADuC812, Philips LPC series, Philips 80C552/554,
      Dallas 320/520/530, Temic 89C51RD2 (including on-chip E2PROM),
      Temic 80C51CC2 and most other standard 40-pin devices like the
      8051FC,RD,RD+, 8052, and so on.

    - Full simulation support of multiple DPTR registers in various
      devices has been added.

    - The uVision2 Debugger now includes a Monitor-51 interface.

    - The uVision2 Editor provides syntax coloring for assembler code.

    - You may now use the context menu in the uVision2 Editor to
      insert the CPU register definition include files.

    - Context Sensitive help is available for library functions and
      error messages.  Position the cursor on a library function call
      or an error message and press the F1 key.

    - Philips 80C51MX support and Dallas 80C390 contiguous mode support
      in the PK51 package.  LX51 Extended Linker/Locater.

    - New PDF Version of the Getting Started, C51 and A51/Utilities 
      User's Guide.

    - Debugger Interface for Triscend E5 CSoC (more information 
      is provided in the file C51\HLP\Readme_for_TE5_UV2.TXT).

    - No limitation on number of segments, publics in object files.

    - C51 variable names can be up to 256 characters long.


2.  uVision2 Integrated Development Environment

    This release includes uVision2 for Windows which is an integrated
    development environment that encapsulates the following:

    - a project manager
    - integrated make facility
    - tool configuration
    - editor
    - a powerful debugger

    Using our tools, uVision2 allows you to write, compile, and debug
    your programs.  The example programs provided on this CD are
    designed to work with uVision2.


3.  Compiler Enhancements

    C51 Version 6.11 contains the following improvements:

    - Three new Optimize Levels focus on code density and reduce
      the code size of your application by 5-15%.
  
      OPTIMIZE(7) Extended Access Optimization: This optimizer level
      uses the DPTR for register variables.  Pointer and array accesses
      are optimized for both speed and code size.

      OPTIMIZE(8) Re-use Common Entry Code: This optimizer level moves 
      common function entry code to the beginning of a function to
      save code memory.  This is the new default optimization level.

      OPTIMIZE(9) Common Block Subroutines:  This optimizer level
      detects and merges multiple instances of common instruction
      sequences into subroutines.  This optimization provides the
      greatest benefit to large, monolithic modules.

    - The enum data type automatically adjusts its size to 8 or 16
      bits.

    - Support is available for Atmel, Philips, and Temic dual DPTR
      and functions the same as the Dallas 80C320, 80C520, 80C530, 
      and 80C550 (ref: C51 User's Guide, chapter 5).

      Atmel Devices: Dual DPTR's are currently available on the 
      AT89S8252. The C51 directive MODA2 generates code for dual
      DPTR's on Atmel and NOMODA2 disables dual DPTR usage.

      Philips and Temic Devices: Dual DPTR's are available on 
      several Philips devices. The C51 directive MODP2 generates 
      code for dual DPTR's and NOMODP2 disables dual DPTR usage.

    - A new directive, ONEREGBANK, offers enhanced support for
      programs that use a single register bank.  By default, the C51
      Compiler ensures that registerbank 0 is selected during by
      interrupt service routines (ISRs) that are declared without a
      using directive.  This is done by adding the instruction
      MOV PSW,#0 to the entry code.  This is necessary when the using
      directive is omitted on high-priority ISRs that may interrupt
      other low-priority ISRs (that have a register bank specified
      with the using directive).  This also applies to RTX-51 and
      RTX-51 Tiny applications.

      You may now use the ONEREGBANK directive to specify that only 
      registerbank 0 is in your application.  Then, C51 will not 
      generate the additional MOV PSW,#0 instruction for ISRs.
    
    - The C51 directives RET_ISTK, RET_PSTK, and RET_XSTK let you
      unload the on-chip stack and use the reentrant stack for 
      storing the return address.

    - The following ANSI library routines have been included:  modf, 
      strtod, strtol, and strtoul.

    - The C51 directive OMF2 outputs a new object file format for 
      the Extended LX51 Linker/Locater.  With this new format, 16MB code
      space for constants and 16MB xdata space are supported for 
      extended 8051 device variants, like ADuC812, Dallas 390 and 
      others.

    - The C51 directive ROM(D512K) and ROM(D16M) generates code for the 
      Dallas 390 contigious mode.  You need to use this directive together
      with the OMF2 directive.  More information is provided in the file
      C51\EXAMPLES\DALLAS 390\README.TXT.



4.  Assembler Enhancements

    A51 Version 6.11 contains the following improvements:
  
    - Support has been added to provide compatibility with the C
      Preprocessor used in the C51 Compiler.  Now in A51, a standard
      C macro preprocessor expands source text before the source file
      is assembled.  This preprocessor is almost identical to the
      one implemented in the C51 Compiler (refer to the C51 User's
      Guide, chapter 4).  The #include file path specification used
      is obtained from the C51INC environment variable.

    - The INCDIR directive (abbreviation ID) lets you specify the
      paths to assembler include files.  With INCDIR, you may
      supply one or more paths to search for when a $INCLUDE (file)
      directive is processed.  For example:

      $INCDIR (C:\C51\ASM)
      A51 STARTUP.A51 INCDIR (C:\C51\INC,C:\MYDIR)

      The search order for $INCLUDE is:

      a. Current directory (typically, the folder of the uVision2
         project file)

      b. Paths specified with $INCDIR

      c. Path derived from the bin directory with ..\asm path
         (C:\Keil\C51\Asm in default installations).

    - The A51 Assembler now supports the following pre-defined Macros:

      __FILE__   name of the file being translated

      __LINE__   current line number in the file being compiled

      __TIME__   time when the translation was started

      __DATE__   date when the translation was started

      __STDC__   defined to 1

      __A51__    version number of the A51 Assembler (for example,