KUKA Roboter GmbH

Windows 

Nonproprietary Real-Time Extension Technology 

Combines Windows ® CE & Windows ® XP Embedded 

on single or multicore CPUs 

KUKA Roboter GmbH 

Global Sales Center 

Hery-Park 3000 

D-86368 Gersthofen 

Germany 

Introduction 

Tel.: +49 821 4533-3768 

Fax: +49 751 4533-2129 

Email: Introduction 

RainerGallus@kuka-roboter.com 

Web: www.kuka-rtos.com Edition: April 2008

CeWin Version 3.5 

Microsoft Windows® XP 

Microsoft Windows XP is the dominant operating system used today in x86 desktop PCs 

worldwide. It has a very familiar graphical user interface, but due to the absence of realtime 

ability it is not suitable for most industrial applications. The real advantages of 

Windows XP, however, are to be found in its widespread application base and from both its 

acceptance and familiarity by users. To make Windows XP useful for industrial real-time 

applications, such as industrial automation, motion control, test and measurement, medical 

devices and defense systems, KUKA Roboter GmbH has developed a solution which 

eliminates the disadvantages of Windows XP without giving up its advantages. 

Microsoft Windows CE 

Microsoft Windows CE is a widespread real-time operating system (RTOS) also produced 

by Microsoft. Several versions of Microsoft Windows CE are available for different 

processor architectures (ARM, MIPS, Intel 80x86 and others). Microsoft Windows CE 

traditionally runs standalone on a single processor and uses the hardware resources RAM, 

ROM, I/O hardware, and so on, exclusively. 

CeWin: Windows CE and Windows XP Together on a Single PC 

KUKA Roboters CeWin product family complements Windows XP with the Windows CE 

real-time operating system; allowing both to coexist and run concurrently on the same 

single-processor PC (regardless if it is a single core or a multi-core CPU system). Create 

real-time applications taking advantage of the full capabilities of Windows XP without the 

need for a second dedicated controller. The application gets the best of both worlds. 

To make this possible, a software-only real-time extension technology for Windows XP has 

been developed which guarantees deterministic response on interrupts which are targeted to 

Windows CE. These interrupts can be generated by any PCI or ISA PC plug-in board. 

Windows XP is fully preemptable by interrupts generated by real-time devices. 

Single Core Systems: 

As long as at least one Windows CE thread is active, the processor’s execution time is 

available exclusively for Windows CE. Windows XP runs only if all Windows CE threads 

are idle. Windows XP effectively operates as the Windows CE idle thread. Virtual machine 

technology or time slicing is not utilized by CeWin. During all real-time processing, 

Windows CE has exclusive use of the processor. Conversely, as long as no real-time 

interrupts are being received, Windows XP has exclusive control. No proprietary 

modifications are made to either OS which insures binary compatibility with standalone 

versions of each OS. 

Dual Core or Multi-Core Systems: 

When CeWin is operating in exclusive mode on a dual or multi core system, Windows CE 

usually runs on the last processor core while Windows XP runs on all other. Both operating 

KUKA Roboter GmbH Page 2


systems operate completely concurrently and independent from each other. In this operation 

mode, latencies and jitter is dramatically reduced compared with a single core system. 

Target Markets 

� PC-based industrial automation including PLC, motion control, robotics, CNC 

� Real-time test and measurement/data recording 

� Medical devices and equipment 

� PC and HMI add-on for existing Windows CE applications 

� Windows CE target simulation with real-time behavior and hardware access 

Technical features 

� Use of Windows CE as a headless RTOS concurrent with Windows XP 

– Access to the entire Windows XP Win32 API 

– TCP/IP Stack, DCOM, ISAPI, ASP, SOAP etc. 

– Runtime environment for C, C++, C#, Visual Basic etc. 

– Optional products 

� Software-only solution, no additional hardware necessary 

� Uses standard Microsoft development tools for both Windows XP and Windows CE 

� APIC support 

� Multiprocessor support 

� Graphical real-time analysis tools (Kernel Tracker, Profiler etc.) 

� High-resolution real-time timer, granularity 0.8 microseconds 

� Hardware access to ISA and PCI plug-in boards 

� Communication between Windows XP and Windows CE via shared memory 

� Access to the Windows XP hard disk via directory share 

� Date/Time synchronization between Windows CE and Windows XP 

� CeWin can start as a service – no user login to Windows XP is required 

� User specified CPU sharing between Windows CE and XP. Eliminate Windows XP 

CPU time starvation during special situations 

� Auxiliary system clock with frequencies up to 25kHz 

� Most common Microsoft-supplied HALs are compatible 

� Support for Microsoft Windows CE V5.0 



Commercial Features 

� No need for additional intelligent co-processor boards nor separate control hardware 

� Reduction of hardware costs; eliminates a second CPU 

� Less hardware components; increased reliability (MTBF) 

� More compact control systems possible 

� Nonproprietary; built on COTS operating systems 

� Full support from a company with worldwide locations 

� Short learning curve 

– Known development tools: Visual Studio 2005, Platform Builder, eMbedded 

VC++ 

– Full Win32 API 

� Re-use of existing Windows CE software and know-how is possible 

Application Development 

A CeWin development seat provides a BSP in the form of a Microsoft Platform Builder 

project. The CeWin SDK contains all the necessary header and library files needed to build 

CeWin applications. Wizards are available to assist in generating new applications. 

Components for integration into Windows XP Embedded images are also included. As 

Windows CE and Windows XP run on the same processor, a separate host is not required 

for application development. 

The Windows CE application is edited, compiled and debugged using the tools provided by 

Microsoft eMbedded VC++, Visual Studio 2005 and Platform Builder. The Windows XP 

application is developed using Microsoft Developer Studio. Develop, test and debug the 

actual target, as opposed to a simulated target, on the same PC. 

CeWin is started and stopped using the Uploader tool. The Uploader can be used as a 

standalone Win32 application or integrated directly into a CeWin application using the 

supplied Uploader library. 



Communication between Windows CE and Windows XP 

The CeWin shared memory TCP/IP network can be used for communication between 

Windows CE and Windows XP. For this purpose, two corresponding network drivers have 

been developed; one for each operating system. Using the Windows XP built-in IPforwarding 

feature, Windows CE can access other systems which are connected to the 

Windows XP external network interface. Also, Windows CE applications have access to 

Windows XP shared network directories. 

CeWin applications using the TCP/IP network can be separated and communicate using a 

physical Ethernet line without having to modify the original application. Developers do not 

have to rely on a proprietary API or an interface having limited support. 

For a more direct TCP/IP connection to systems outside of the PC, an additional Ethernet 

card supported by Windows CE is used. The second Ethernet card is controlled directly by 

Windows CE and can exist alongside the Ethernet card used by Windows XP. Using the 

standard TCP/IP protocol, any additional Windows CE products can communicate with 

CeWin, e.g., development systems like Platform Builder or Kernel Tracker. 

For the runtime system, TCP/IP sockets can facilitate proprietary communication protocols 

between Windows XP and Windows CE applications. Alternatively, standard mechanisms 

like DCOM or SOAP may also be used. From the point of view of Windows CE or 

Windows XP applications, there is no difference between running under CeWin on the 

same PC or distributed across separate systems. 

In addition to the TCP/IP virtual network, direct shared memory communication is also 

supported. A Windows CE application can allocate a chunk of memory from the shared 

memory area. The allocated memory can be read from or written to by either Windows CE 

or Windows XP. CeWin provides a shared event mechanism for Windows XP that can be 

used to coordinate reading and writing of the shared memory area. 



Traditional Solution: 

TCP/IP on Ethernet 

Target with Windows CE PC with Windows 

CeWin Solution: 

PC with Windows 



CeWin 

The CeWin interface driver allocates the memory to be occupied by Windows CE during 

the Windows XP boot process. The allocated memory is protected in hardware by the x86 

MMU, is guaranteed to be fixed and will not be swapped to disk. Windows XP is not aware 

of and has no access to this memory. 

CeWin is started using the Uploader tool. The Uploader queries the CeWin interface driver 

for the location of the memory allocated for Windows CE code and data. Next, the 

Windows CE image is read from the disk and copied into that memory. 

After the code and data are relocated to the loading address, Windows CE is started using 

its init() function. As soon as all initialization threads are idle, the init() function returns and 

the Uploader terminates. From this point forward, Windows CE will be activated only by 

real-time interrupts followed by task scheduling. All Windows CE threads run in ring 3. 



Singlecore Systems: Activation of CeWin by Interrupts 

PC with Windows 

Hardware 

Interrupt 

The interrupts for Windows CE, as well as for Windows XP, are received by the CeWin 

interface driver directly from the PC’s interrupt controller. KUKA Roboters real-time 

extension technology assures that the interrupts assigned to Windows CE always have 

higher priority than anything occurring in Windows XP; including Windows XP interrupts. 

The technology guarantees Windows XP is fully preemptable. 

All real-time interrupts initiate the execution of the corresponding Windows CE interrupt 

service routine (ISR) within a few microseconds. After returning from the ISR, but before 

returning to Windows XP, Windows CE checks for and activates any threads ready to run. 

After all running Windows CE threads return to the idle state, CeWin transfers control back 

to Windows XP. 



Exception Handling of Windows CE 

Whenever Windows CE is activated via the ISRs, a new exception table is loaded by a 

single assembler instruction. Therefore the exception handling for page faults, debugging, 

and so on is exactly the same for CeWin as it is for Windows CE running standalone. The 

Windows XP exception table is reloaded before falling back to Windows XP. 

The arithmetic co-processor may be used within CeWin without any restrictions. Since it is 

possible that the interrupted Windows XP has the arithmetic co-processor in use, its state is 

saved if Windows CE requires its use and restored before returning to Windows XP. 



Dualcore and Multicore Systems: Exclusive Mode Operation 

When CeWin operates in exclusive mode (only available on 

multiprocessor/multicore systems) the last CPU core in the system is dedicated 

to Windows CE. All remaining CPUs are used by Windows XP. 

The following diagram, illustrates the flow of control on a dual core system: 

WinXP 

IRQ 

� 

WinXP 

ISRs, 

DPCs 

WinXP 

Processes 

� 

Realti 

me 

IRQ 

� 

WinCE 

ISRs 

WinCE 

threads 

Core 1: Core 2: 

Operating states of CeWin in exclusive mode 

� Exception-handling or a higher priority interrupt becomes 

outstanding. 

� Interrupt Service Routine optionally starts a new thread and then 

finishes. 

Note: When running CeWin in exclusive mode Windows XP will never be interrupted. 

Application and interrupt processing run concurrently and independently on both CPU 

cores. There is no need in Windows CE to become idle. 

Hardware Requirements 

� Minimum 266MHz Pentium® II processor (500MHz recommended) 

� Minimum 128MB RAM 

� 32MB available hard disk space 

Operating System Requirements 

� Microsoft Windows® XP SP2 

� Microsoft Windows® XP Embedded SP2 

� Microsoft Windows® CE V5.0 

KUKA Roboter GmbH Page 10 

�


CeWin Product 

CeWin supports the full functionality of Windows CE: 

� Access to the local Windows XP hard disk (e.g., to load the user applications) 

� Win32 Windows CE subset API; including C++ Support 

� Windows CE console access by Telnet 

� Pre-configured Windows CE images with several fixed memory configurations 

� Additional OS features cannot be included 

� Development environment: eMbedded Visual C++, Visual Studio 2005 and 

Windows CE Platform Builder 

� Only one user process is allowed 

� Support of TCP/IP communication between Windows XP and Windows CE but 

with no routing (IP Forwarding) support 

Licensing 

The CeWin product license from KUKA Roboter GmbH only consists of the coupling 

mechanisms allowing both operating systems to run concurrently on the same PC. It does 

not include the required Microsoft licenses for Windows XP and Windows CE. Those must 

be procured from a Microsoft distributor. CeWin is installed only after licenses for both 

Windows XP and Windows CE have been received. 

About KUKA Roboter GmbH 

KUKA Roboter GmbH is the number one European industrial robot manufacturer and a part of 

KUKA AG Group. KUKA Roboter GmbH specializes in real-time software, operating systems, 

motion control, graphical user interfaces (GUI), handhelds, dynamic algorithms, PC-based hardware 

development and application programming. KUKA Roboter GmbH globally markets real-time 

extension technology for automation and robotics as well as test and measurement instrumentation, 

and medical devices and equipment. For more information on KUKA Roboter GmbH, contact Mr. 

Rainer Gallus, Sales and Marketing – Real-Time Products. Phone: +49 821 4533-3768 or 

RainerGallus@KUKA-Roboter.de. Online information can be viewed at www.kuka-rtos.com. 

© 2008 KUKA Roboter GmbH. All rights reserved. 

Information contained herein supersedes previously published specifications and is subject to change without notice. 

Trademarks are property of their respective owners.

KUKA Roboter GmbH

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