release.txt

Keil C51 V6.21的安装程序_Keil C51下载

      /****************************************************/
      /*         Release Notes for Version 6.21           */
      /*           8051 DEVELOPMENT TOOL KITS             */
      /****************************************************/

This file contains release notes and last minute changes relating
to the 8051 Version 6.21 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 6.21

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 6.21

    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 6.14, Release V6.21 contains the following
    enhancements:

    - 'far' memory support examples are provided for the 16MB memory
      space of the ADuC812 and E2PROM area of the AtmelWM 89C51RD in
      the folder C51\Examples\FarMemory.  Problems with the 'far' memory
      type have been fixed and new macros for absolute memory access 
      for the 'far' memory are added in ABSACC.H.

    - Enhanced L51_BANK.A51 file. 

    - Code Optimization has been improved for more register variables and
      better code re-arrangement in if/else constructs.

    - Directive MODDA enables support for Dallas 390 Arithmetic Unit.


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 6.21 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.

    - The configuration file C51\LIB\XBANKING.A51 allows you to configure
      'far' memory support for various devices.  Configuration Examples
      can be found in the folder C51\Examples\FarMemory.

    - Code Optimization has been improved for more register variables and
      better code re-arrangement in if/else constructs.

    - Directive MODDA enables support for Dallas 390 Arithmetic Unit.



4.  Assembler Enhancements

    A51 Version 6.21 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