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Information in this article applies to:

  • RTX251 Version 2.14


What's new in RTX251 Version 2.14?


The following README.TXT file is included with the RTX251 installation.

         /*       Release Notes to RTX-251 Version 2         */

This file contains release notes and last minute changes relating to the
RTX-251 real-time operating system.  Information in this file, the
accompanying manual, and software is Copyright (c) 1997 Keil Germany/USA
and Mettler & Fuchs Switzerland.  All rights reserved.

- The Keil DK251/CA251 package must be installed prior to RTX-251 installation.

- This RTX-251 does not include any CAN support

Example Programs
Several example programs have been included in the RTX251 directory.
These files demonstrate how to use the project manager as well as
how to use µVision and dScope to generate and debug RTX251 applications.

RTX251\SAMPLE    use message passing of RTX251.
RTX251\INTRPT    shows user interrupt routines.
RTX251\TRAFFIC2  the traffic example discussed in the RTX51/251 user's guide,
                 this example is only provide for the SOURCE mode running
                 under dScope.

The RTX251 examples contain project files that support the different
CPU modes of the 251 and evaluation boards.

Project File    Description
BINARY.PRJ      Generates the exmaple program in BINARY MODE.

SOURCE.PRJ      Generates the exmaple program in SOURCE MODE.

MCB251.PRJ      Generates the example program with I/O routines for the
                Keil MCB251 Evaluation Board Version 2 in SOURCE MODE.

Debugging with Monitor-251 on Keil MCB-251
You can debug RTX-251 applications with Keil Monitor-251.  However,
depending on the configuration, Monitor-251 requires certain interrupt
vectors for the serial interface.  Monitor-251 as configured on the Keil
MCB-251 board inserts an Interrupt Vector for the on-chip UART (SIO INT)
or the external UART (INT0).  The actual interrupt vector used depends
on the UART you are actuall using.

In addition to the above interrupts, Keil MCB-251 uses the NMI vector of
the Temic 251 derivatives and the TRAP interrupt vector.  To work with
RTX-251 you must therefore modify the RTXCONF.A51 file and comment out
the interrupt vector generation for INT0, SIO INT and NMI INT.  This is
shown below.  In addition you must use the RESERVE directive on the L251
invocation as described in the MCB-251 user's guide.

         ; Do NOT include the Timer 0 Vector  (INT-1)
;        INT_ENTRY      0   (NO INT0 Vector, when using external UART)
         INT_ENTRY      2
         INT_ENTRY      3
;        INT_ENTRY      4   (NO SIO INT Vector, when using on-chip UART)
         INT_ENTRY      5
         INT_ENTRY      6

Note:  This sequence appears 3 times in the RTXCONF.A51 file.  We have
provided a file RTX_MON.A51 in the examples directory which has already
the required modification.

XDATA RAM Requirements
RTX-251 is using XDATA RAM.  The default range for XDATA RAM is 01:0000H ..
01:FFFFH.  This makes it compatible with existing 8051 hardware.  If your
target hardware does not provide RAM in this area, you can use the L251
CLASSES directive and specify the XDATA area in the address range 00:0000H ..

Reentrant Functions
C251 Version 2 supports reentrant functions on the HARDWARE STACK of the 251.
Therefore RTX-251 does not longer need any special handling for re-entrant
functions.  As a consequence you can use C251 Version 2 reentrant functions
without any restrictions.  The restrictions described in the RTX-251 user's
guide do not longer apply.

Sales and Technical Support
We at Keil Software are dedicated to providing you with the best
development tools and the best sales and technical support.  If you
experience any problems or have any questions about this product,
contact one of our offices for assistance.

In the USA...                           In Europe...

KEIL Software, Inc.                     KEIL Elektronik GmbH
16990 Dallas Parkway, Suite 120         Bretonischer Ring 15
Dallas, Texas  75248-1903               D-85630 Grasbrunn, Germany

Sales/Support (800) 348-8051            Sales   +49 89 456040-0
                                        Support +49 89 456040-24
BBS           (972) 713-9883            BBS     +49 89 4606286
Fax           (972) 735-8055            Fax     +49 89 468162
Email         Email



Last Reviewed: Sunday, April 30, 2000

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