Fall 1998 Let’s Embed the World!

SoftwareVersions

We constantly strive to improveour products by addingenhancements and correctingbugs as quickly as possible.Check our web site at

for thelatest updates.

The following table lists theversions of our 8051, 251, and166 development tools that weare currently shipping.

C51.................V5.50aC251...............V2.14C166...............V3.12RTX51 ............V5.10RTX251 ..........V2.14RTX166 ..........V3.10a

http://www.keil.com/

10 Years of C51Since its market introduction in 1988,the Keil C51 Compiler has becomethe leading C compiler for the 8051microcontroller family. No other 8051C compiler generates more efficientcode for your embedded applications.That's why more than 25,000 usersworldwide use the Keil advantage fortheir 8051 projects.

Visit us at ESC West 1998November 2-5

San Jose Convention Center

San Jose, California

Contact our Dallas

office for

free Passes!

800.348.8051

We are currently shipping C51 Version5.50. This release integrates severalenhancements that make your 8051application development easier.

Dual data pointer support forAtmel and Philips devices.Specify for the AtmelAT89S8252 and other compatibledevices. Use for Philipsdevices with dual data pointers.

The ability to disable specificlinker warnings. Use the

linkercontrol (or for short) todisable specific linker warnings.

�

�

MODA2

MODP2

DISABLEWARNINGDW

.

For example,

disables linker warnings 1, 2, and 3.

Monitor support for code bankingtarget hardware. We have examplesand application notes for the newcode banking monitor available. Wehave installed and tested the newmonitor on our MCB520 andMCB517 evaluation boards. Check

for more details.

If you haven't alreadyupdated your V5.compiler, call our salesdepartment today tofind out how.

When you needtechnical support afterhours, remember tocheck the supportsolutions database onthe world wide web at:

BL51 myfile.obj DW(1,2,3)

�

www.keil.com

x

Web-BasedSupport

http://www.keil.com/support/

Booth #1922

Call Today! 800-348-8051 http://www.keil.com/

Software News

RTX51 SemaphoresWe frequently hear the question,“How can I call from multipletasks in my RTX51 application?”Since is not reentrant,problems arise if it is invoked frommore than one task. RTX51 providesbinary semaphores which you can useto guarantee exclusive system access.

printf

printf

First, you must define a semaphorefor the function. This is anumeric constant between 8 and 15.We defined ours .

Next, in your initialization code, youmust set the semaphore. Thefollowing code shows how.

printf

SM_PRINTF

Dual Data PointersOne of the slowest operations of the8051 is accessing XDATA or CODEusing the DPTR register. This isespecially true if you move memoryfrom CODE to XDATA or evenfrom one XDATA buffer to anotherXDATA buffer. That’s where thedual data pointers offered bySiemens, Dallas Semiconductor,AMD, Atmel, and Philips come in.

Keil C51 V5.5 library routines suchas and use dualdata pointers whenever possible.

As an example of the performance

memcpy memcmp

improvement, we compared movingmemory on a standard 8051 runningat 12MHz with a single DPTR to aDallas Semiconductor 320 runningat 12MHz with dual DPTRs. Thegraphs pictured above show theincrease in performance.

When moving large buffers (100bytes or more), dual data pointers letyou move data nearly 4 times faster(on the Dallas Semiconductor320/520). Results on other chipsmay vary.

Forthcoming releases of C51 willsupport optimizations for dual datapointers. Contact our salesdepartment for details.

os_send_token (SM_PRINTF);

os_wait (K_MBX + SM_PRINTF,255, 0);

printf ("...");os_send_token (SM_PRINTF);

OVERLAY(* !?PR?PRINTF?PRINTF)

This makes sure that the first task to“get” the semaphore succeeds. Thefollowing code should be usedwherever is invoked.

This code “gets” thesemaphore, calls , and “puts”the semaphore back.

Since the function is notreentrant, but is invoked from multipletasks, the linker will complain aboutmultiple calls to the segment.The problem is that the linker does notknow how to overlay the data area.So, you must tell it where thefunction fits into the program’s calltree. Since it is called from multipletasks, it does not fit into the call treeof any one task. Therefore, it must bemade a separate segment that is notsubject to overlaying. The followinglinker command does the trick.

An example program ( )is available on the Keil FTP site at

printf

printfprintf

printf

printf

printf

PFSEMA.ZIP

ftp.keil.com.

Page 2 Fall 1998

Visit us on the World Wide W

After attending a Keil training class,you’ll know where to start and how toget your project completed.

Our classes are designed for anyoneresponsible for embedded softwaredevelopment. Engineers as well asmanagers will learn from these classes.Attendees should have a good workingknowledge of programming, however,knowledge of the C language is notrequired.

You may enroll on the world wide webat , sende-mail to , or call us at

.class@keil.com

800-348-8051

http://www.keil.com/training/

Let’s Embed The World!

on our key in-house systems.

The software currently in use hasbeen tested and non-compliantsystems will be updated prior to themiddle of 1999. Key suppliers,while possibly being affected, havelimited impact on our ability to shipproduct. In addition, our ability toaccess customer and vendor datawill not be affected by the datechange. This includes our ability toprovide technical support to endusers of our products.

For a complete report on this topic,visit our web site or contact yourtechnical support representative fordetails on how you can obtain thecomplete Keil Y2K Statement.

When you start a new embeddedproject, the last things you need arewasted time and costly mistakes thatcould have been avoided. Enroll inan 8051 or 166 training class fromKeil Software and let us show youthe tricks and traps of your targetarchitecture while teaching you howto get fully-functional applicationsup and running.

Training Courses

Y2K ComplianceAs you are all aware, there is a greatdeal of concern regarding thepossible effects of date-relatedcomputer crashes at the turn of themillennium. The severity of theseeffects range from none to thecatastophic depending on whichreports you review and your level ofreliance on computer-based devicesand software.

We have reviewed our dependenceon computer systems and softwarehere at Keil and have come to theconclusion that the millenniumchange will have little or no impact

MCB517ACEvaluation BoardThe MCB517AC single-boardcomputer lets you build and testapplications for the Siemens80C517A. This high-endmicrocontroller provides thestandard 8052 on-chip peripheralsplus A/D, 8 data pointers, and ahigh-speed math unit. All of thesefeatures are directly supported bythe Keil 8051 development tools.

The board comes pre-configuredwith MON51 which lets you debugdownload and test both standard andcode banking applications (up to 6code banks). The Keil 2K-limitedevaluation tools for the 8051 areincluded.

The µVision IDE helps you createyour applications and the dScopedebugger lets you download themand test them on the MCB517ACsingle-board computer.

The board supports the ControllerArea Network (CAN) with anexternal 80C91 Siemens CANController. Examples on our website show you how to use theRTX51 Real-Time Kernel to rapidlycreate working CAN programs.

Page 3Web • http://www.keil.com/

MCB517AC Evaluation Board with Code-Banking and CAN

On-site Training is Available forLarge Engineering Groups

Page 4 Fall 1998

16990 Dallas Parkway, Suite 120Dallas, TX 75248-1903

Phone 800-348-8051972-735-8052

FAX 972-735-8055

BULK RATE

U.S. Postage

PAID

Dallas, TX

Permit #9410

Keil Software manufacturesembedded development toolsfor the 8051, 251, and 166.

We believe that technicalsupport and customer serviceare integral parts of everyproduct we sell. That’s whyevery Keil product comeswith 1 year of FREE technicalsupport. These beliefs makeKeil Software the toolscompany of choice for somany silicon vendors and evalboard manufacturers.

Keil Software Compilers andAssemblers are supported byevery major emulator vendor.When you buy from Keil, youcan be assured that you havethe industry’s best supporteddevelopment tools.

Come see us at the EmbeddedSystems Conference in SanJose, CA, to see our latestproducts and services.

Keil Software, Embedded Systems Conference Fall 1997

Call us at 800-348-8051 for free show passes and information.