Cover Story: February 1, 1996
Windows-based EDA tools: shifting into high gear
Jim Lipman,
Technical Editor
Some believe that EDA tools will be moving en masse from Unix-based platforms to desktop PCs. However, reports of Unix's death are greatly exaggerated. For Windows devotees, there is also the question of which version, 95 or NT, is best for EDA tools.
Last summer's release of the Windows 95 operating system (OS) has focused much attention on EDA tools that run on Windows on PC platforms. Many articles have covered movement of EDA tools to Windows, and some people have even predicted the death of EDA design on Unix-based platforms (see Reference 1).
There is more to this story than the issue of whether you choose Windows vs Unix for your electronic-system designs. You must also consider the kind of designs you do, the portions of the design for which you are responsible, and the level of interaction you have with other members of a work group. All of these issues influence your decision about whether you should use Windows- or Unix-based EDA tools or a combination of the two.
EDA segmentation
If you design an ASIC or ASIC-based electronic system, you use tools covering a broad range of design activities. These tools often require different hardware and networking schemes. When deciding what platform and OS to use, logically segment the design methodology. Segmentation lets you consider different operating systems for different portions of the design. Research company Dataquest uses a reasonable EDA segmentation (see box, "Domain segmentation by design methodology"). Dataquest's method divides EDA design into CAE (IC front end), IC CAD (IC back end), and pc-board design.
Historically, EDA vendors have developed many pc-board design tools for PCs, initially for DOS; then, on Windows 3.1 and NT; and, now, for Windows 95 (see Table 1). Many pc-board-design-tool vendors, such as Accel, Ivex, OrCAD, and PADS Software, describe their design-entry and layout tool packages as "shrink-wrapped." In this case, the term indicates that users can employ the tools right from the box and that the tools need little technical support. On the other hand, front- and back-end IC-design tools have traditionally worked on Unix workstations. The greater complexity of IC design over pc-board tasks, until recently, has required the higher performance of workstations over PC platforms. However, the proliferation of Pentium-based PCs, offering performance comparable to low-range- to-midrange Unix workstations, has opened the IC-design market to PC platforms.
Dataquest has forecast worldwide cumulative annual growth rate of EDA tools revenue on various hardware platforms for 1995 to 1999 (Reference 3). Noteworthy facts from that forecast include the high growth rate of Windows NT as an EDA OS relative to all other OSs and that NT shows growth only in the CAE and pc-board groups: IC front-end and pc-board design.
Domain segmentation by design methodology |
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For its EDA Market Trends analyses (Reference 2), Dataquest divides EDA into CAE, IC CAD, and pc-board design. CAE design tasks include those performed on the electronic-system, register-transfer, and gate levels. Examples of such EDA tasks are design specification and partitioning, formal verification, synthesis, timing analysis, design for test, schematic capture, and simulation. Under "miscellaneous" in the CAE group, Dataquest also places simulation-acceleration, emulation, fault-simulation, library-description, and dedicated programmable-logic-design tools. A rough description of Dataquest's CAE tools would be those used for the front end of an IC design in which you do the front-end design tasks yourself or with the assistance of an ASIC vendor.
IC CAD tools include those used for physical and logical design-rule checking, floor planning, FPGA placement and routing, and IC placement and routing for gate-array, cell-based, and custom chips. The ASIC vendor usually does these back-end tasks. An exception in this group might be floor planning, which is becoming more of a front-end task but one strongly tied to back-end placement and routing. The third group, pc-board design, includes EDA tools used to design and place and route pc boards and multichip modules.
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Requirements for an EDA OS
An OS for EDA tools has vastly different requirements from those of an OS for your home computer. Among the hardware and software attributes it should have are:
- Performance equal to or better than the speed of current Sun and Hewlett-Packard workstations used for EDA tasks,
- True multitasking of jobs, allowing you to run a number of EDA tools simultaneously and be able to move data among them,
- Networking capability that lets you share files and data with other members of your work group,
- File security that prevents not only accidental deletion and modification by you or members of your work group, but also by malicious outside personnel,
- The ability to process much data using available memory and efficient management of memory resources,
- Access to large amounts of disk space, either dedicated or on servers, for designing high-density, high-complexity circuits.
When you examine these needs more closely, you'll find that having fast hardware is not enough. Your OS must be able to use hardware resources efficiently, provide communication among members of a design team, and provide an interface that lets you do your work productively. Windows NT and 95 on PC platforms succeed better in these areas than do Windows 3.1 or DOS.
Windows background
A major effort is under way in developing EDA tools for Windows 95. This effort is not the only Windows thrust for EDA vendors, however (see Table 2). Many EDA companies have released or are developing products for Windows 3.1, 95, and NT.
You probably should not even consider 3.1 as a future OS for EDA tasks. It is yesterday's PC OS, and, as a 16-bit OS with poor networking and no pre-emptive multitasking capabilities, it cannot compare with NT or 95. You would probably want some features of NT and 95 when you are using EDA tools. Both are 32-bit systems, offer better performance than 3.1, can link data across applications, and can run most Windows 3.1 applications. They also give you the convenience of long file names.
Windows NT has some benefits that Windows 95 lacks (Reference 4). These benefits include better networking and security features; multiprocessor support; and the ability to run on non-Intel-based systems, including PowerPC, MIPS, and Digital Equipment's Alpha AXP machines. NT requires 12 and 90 Mbytes of memory and disk space, respectively, vs 95's requirement of 8 and 40 Mbytes (Reference 4). This requirement should not be a major consideration, however, because you need and want lots of memory and disk space.
Why Windows instead of Unix?
Even if your company has a major investment in Unix-based platforms, many reasons exist for considering a switch to Windows for EDA tools. For example, Windows offers a performance/price advantage due to the lower cost of both hardware and software (Table 2). This advantage translates to higher productivity per dollar spent for your chip and board designs. Another bonus is that you often can replace two platforms on your desk, one Unix-based and one PC, with a single PC platform.
After value comes the advantage that your EDA tools can link with Windows productivity tools, such as spreadsheets and word processors. This benefit lets you not only move data among EDA tasks, but also print reports or manipulate parameters in familiar desktop applications, such as Microsoft Word or Excel. Windows also gives you a standard interface--a Windows "look and feel"--which many EDA vendors exploit to simplify your learning and using their tools as part of an integrated design suite.
EDA vendors can still make a tool look very similar on Windows and Unix (Figures 1 and 2). Both Viewlogic and Intergraph are broad-based EDA tool suppliers that design tools for both OSs with similar interfaces, simplifying your use of them as you switch between, for example, a workstation in the office and your PC at home. The ability to take work home and to use your own PC to do portions of a design is also appealing. Platform flexibility is particularly beneficial to those who do not want to work overtime in their offices.
Where Windows falls short
You are not going to wake up one morning and find all of your Unix platforms mysteriously gone, only to be replaced by PCs running Windows. There are certain EDA tasks that Unix performs better than does Windows. Also, the track record of Windows cannot begin to approach that of Unix, particularly for the six-month-old Windows 95. In addition, many more EDA applications are running on Unix than on Windows. Even if you can use a Windows-based tool for your design tasks, consider how you may need to interface with other Unix-based tools doing either coupled tasks or tasks sharing a common database.
System robustness, the probability that the application will not crash the system in the middle of a long computation, is also very important. In the early 1980s, if you were doing IC design on a workstation using available EDA tools, you ran the risk of losing hours of design if your system went down. Today's tools, on both workstations and PCs, are much better at handling today's high-complexity design tasks. Because Unix is more mature than Windows, its programmers have had more time to solve the problems that can lead to OS crashes. In addition, some designers have concerns that Windows 95 is less robust than NT and lacks some of NT's memory-protection features.
Also, remember that Windows is not hardware, and just because NT has multimachine flexibility does not mean that an EDA tool designed to run on NT on an Intel-powered machine can also run on non-Intel machines. If you buy tools for non-Intel processor computers, make sure that they will run on such platforms.
You can generally characterize back-end design tasks as CPU-intensive and needing to access large amounts of data without much designer interaction. Even with Windows NT and 95, such design jobs will probably remain resident on Unix platforms, with their large amounts of memory (256 Mbytes is typical), large disk space (either on the platform or through a networked server), and fast CPU-to-disk transfer speed.
Table 2--Windows requirements from a sampling of EDA vendors
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| Company | Product | Use | Price | CPU/clock | Memory (Mbytes) | Disk (Mbytes) Minimum | Recommended Windows |
|---|
| Windows | Unix | Minimum* | Recommended | Minimum* | Recommended* |
|---|
| Altera | PLS-ES
PLS-ADV
PLS-Flex8
PLS-Magnum
PLS-WS | Entry PLD design
Advanced PLD design
Flex 8000 PLD design
Top-of-line PLD design
PLD design for workstations | $495
$1495
$1495
$8395 |
$7495 | 486/33 to Pentium/60 | Pentium/90 | 16 to 32 | 32 to 64 | 30 to 60 plus 20 to 70 swap | NT |
|---|
| Cadence | Allegro | PC-board layout | $23,000 | $23,000 | 486/66 | Pentium/100 | 32 |  | 150 | NT/95 |
|---|
| CAD-Migros | Spice-It
Whole Enchilada | Schematic capture and Spice
Schematic capture, Spice, and pc-board layout | $1895
$3995 | | 486/66 | | 8 | 16 | 20 | NT |
|---|
| CAST | SCVL
SCVL-S | VHDL library/TTL, and memory
Synthesis VHDL, TTL parts | $1495
$4495 | $2995
$4495 | 486/50 | | 12 | | 75 | NT |
|---|
| Crosspoint | CPTools | FPGA design | $2995 | $5995 | 486/66 | | 16 | | 80 | NT |
|---|
| Data I/O | Synario Entry | PLD | $2995 | | 386/33 | | 8 | 16 | 20 | NT |
|---|
| Dynamic Soft Analysis | BetaSoft | PC-board thermal analysis | $7000 | $10,000 | 486/50 | | 8 | | 12 | 95 |
|---|
| Escalade | DesignBook | Design multientry and configuration | $10,000 | | 486/50 | | 24 | 32 | 100 | 3.1 |
|---|
| Exemplar | Galileo | FPGA design environment | Starts at $12,000 | Starts at $22,000 | 486/50 | | 24 | | 10 to 20 | NT |
|---|
| Frontline | Pure Speed Development
Pure Speed Overdrive | Interpreted and gate-level Verilog simulator
Interpreted, gate-level and compiled Verilog simulator | $5000
$9000 | $12,000
$24,000 | 486/50 | | 8 | | 20 to 25 | NT |
|---|
| HP EEsof | Touchstone Lite
Touchstone
Libra
J-Omega | Linear-frequency-domain Entry-level circuit analysis
Linear-frequency-domain Circuit analysis
Nonlinear-frequency-domain circuit analysis/microwave
nonlinear-frequency-domain Circuit analysis/RF | Starts at $8000 | Starts at $18,500 | 486/33 | Pentium/90 | 32 | | 500 plus 100 swap | NT |
|---|
| HyperLynx | BoardSim | Signal-integrity analysis | $1895 to $3495 | | 486/33 | | 8 | | 2 | NT |
|---|
| Intergraph | VeriBest
VeriBest
VeriBest
VeriBest | Schematic capture
PC-board design
Verilog simulator
Synthesis
Design-methodology manager
Various net listers | $750
$30,000
$7500
$18,000
$1000 | $1000
$35,000
$12,500
$22,500
$2000
$1500 | 486/66 to Pentium/100 | | 16 to 64 | | 1000 | NT/95 |
|---|
| MicroSim | PSpice | Spice simulator | $995 | | 486/33 | | 4 | 8 | 50 | 95 |
|---|
| MINC | PLD Designer | PLD-design package | $1995 to $8500 | $4595 to $18,000 | 486/33 | | 8 | 12 | 20 | NT |
|---|
| OrCAD | Capture
Simulate
Layout Ltd
Layout
Layout Plus | Design entry
FPGA/CPLD timing simulator
Entry-level pc-board design
PC-board design/autorouting
Rules-based pc-board design | $995
$2495
$1995
$4995
$9995 | | 486/66 | | 8 | 16 | 30 | NT |
|---|
| Viewlogic | ViewDraw
SpeedWave
VCS
Motive
XTK | Schematic editor
VHDL simulator
Verilog simulator
Timing analysis
Signal-integrity and crosstalk analysis | $1995
$5000
$10,000
$20,000
$28,500 | $6000
$6000
$30,000
$36,000
$50,000 | 486/66 | | 16 to 32 | | 500 | NT |
|---|
NT's edge over 95
Table 2shows that most EDA vendors are recommending Windows NT to their customers. Viewlogic Systems recently introduced the Workview Office suite of EDA tools that runs on Windows 3.1, 95, and NT. Viewlogic offers three reasons for advising designers to go with NT: better data and application security, access to scalable hardware platforms, and better disk management. Viewlogic also sees no incompatibility with 3.1 programs, because almost all applications written for 3.1 will run on either 95 or NT without modification.
Unlike 95, NT requires a user ID and password to boot up your computer and has pre-emptive multitasking for 16-bit Windows applications. "Pre-emptive multitasking" means that a current application need not consent to an interruption by another application. For example, if you are using NT with older programs, they cannot hog the CPU. Pre-emptive multitasking lets you efficiently interface with one application while another, such as a simulation, runs in the background. Both 95 and NT have pre-emptive multitasking for 32-bit applications.
Another feature NT offers but 95 lacks is memory protection for 16- and 32-bit applications. If a 16-bit application crashes under NT, it does not bring down the entire OS or affect another application that may be running. With this protection, you do not have to worry about your place-and-route program's crashing after running 8 hours just because your op-amp Spice analysis crashed. Windows 95 has memory protection for 32-bit, but not 16-bit, programs. You can also configure NT to restart automatically if the system goes down.
NT has security features that 95 lacks. You can configure the NT file system (NTFS) to restrict access to systems and data, thus preventing accidental or purposeful file deletion or damage to EDA applications. You can use NT in a work group with security for all files. NTFS also lets you selectively secure files on per-file, -directory, and -volume levels. Flexible security is important when members of a work group must access different design files.
NTFS also has better memory-allocation capabilities than does Windows 95's file-allocation-table (FAT) system. FAT has a 16-kbyte allocation table, meaning that even small files still take 16 kbytes. Large allocation tables can result in much wasted disk space; for example, a file of 16 kbytes plus 1 byte takes 32 kbytes of space. NTFS has a default allocation size of 512 bytes, which you can change. A smaller cluster lets you use disk storage more efficiently.
Finally, you must consider speed: How fast will your programs run on Windows NT vs 95 or 3.1? The answer to this question is unknown, but indications are that 95 and NT run at about the same speed and that both run faster than 3.1. Developers at National Instruments have run some preliminary benchmarks (Reference 5) with a test application on all three OSs. Their tentative conclusion is that 95 runs 25 to 50% faster than 3.1 and that NT runs as much as 10% faster than 95.
Looking ahead |
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With the increasing number and variety of EDA tools on Windows-based platforms, PCs are becoming more like engineering workstations in CPU performance, hard-disk capacity, memory size, and networking capability. Although improvements in these areas come at a price, economies of scale predict that PCs will continue to offer more bang for the buck due to the difference in sales volume between themselves and workstations.
EDA companies, recognizing the potential for Windows-based tools, are changing business plans to take advantage of the new design environment. One example is Antares, a privately held company formed late last year and funded by Mentor Graphics. Antares was founded as a supplier of shrink-wrapped, Windows-based EDA software for FPGA, ASIC and pc-board design. The company comprises "Centers of Excellence" in simulation, logic synthesis, and integrated design. Current Centers of Excellence are Model Technology for simulation and Exemplar for synthesis.
 Future electronic-design environments will comprise client/server networks, with both Windows and Unix servers and client platforms consisting almost exclusively of PCs with a Windows OS ( Figure 3). Networks will also tie clients into nonengineering corporate functions, such as purchasing and data management, resulting in a more tightly integrated project-development environment. NT appears to be the Windows OS of choice for the electronic-design community, but this fact doesn't preclude Microsoft from introducing a new OS in the future that will contain the best features of NT and 95.
Finally, many Windows-based EDA tool prices are too low, based on the (mistaken) belief that EDA vendors should price their PC-based tools substantially lower than comparable workstation-based tools. As more sophisticated tools enter the Windows realm, look for average prices to increase, despite increased competition.
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Where does this leave Unix?
For many reasons, Unix's disappearance in the foreseeable future seems unlikely. Companies have too much invested in Unix-based hardware to just throw the machines on the junk heap. Second, certain types of EDA tools, such as back-end IC-design tools, run well on Unix, and running comparable tools on PCs with Windows makes little sense. Examples of such tools include those that are CPU-intensive, noninteractive, and not tightly linked to other EDA tasks.
Finally, some users don't acknowledge that Windows is a viable alternative to Unix for many EDA design tasks. For those users, Unix is an old, reliable friend. To them, I say, "Good luck," for the times, they are a'changin'.
You can reach Technical Editor Jim Lipman at (510) 606-1370, fax (510) 606-1177..
References
1. Collett, Ronald, "Unix: R.I.P.," Electronic Engineering Times, Aug 7, 1995, pg 31.
2. "Electronic Design Automation Market Trends," Dataquest Report CEDA-WW-MT-9501, Aug 28, 1995.
3. "CAD/CAM/CAE and GIS worldwide 1994 Forecast," Dataquest Report CCAM-WW-MS-9501, May 29, 1995.
4. "Windows 95 and Windows NT Workstation Product Comparison: How to choose the right mix for you, now and in the future," Microsoft Windows NT Workstation Market Bulletin, July 1995.
5. Strassberg, Dan, "Virtual-instrument software goes 32 bit," EDN, Jan 4, 1996, pg 77.
6. "Windows NT Workstation in Engineering and Science," A White Paper from the Business Systems Technology Series, Microsoft Corp, February 1995.
Acknowledgments
Thanks to Richard Curtin of Frontline Design Automation, Greg Raley of Sage EDA, Joy Burd of Ansoft, and Gary Smith of Dataquest for their comments and suggestions. A special thank you to Karen Wills of Viewlogic for background information on Microsoft Windows.
| Representative manufacturers of EDA tools for Windows
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When you contact any of the following manufacturers directly, please let them know you read about their products at the EDN Magazine WWW site. |
Accel Technologies
San Diego, CA
(619) 554-1000 |
Actel
Sunnyvale, CA
(408) 739-1010 |
Altera
San Jose, CA
(408) 894-7000 |
Ansoft
Pittsburgh, PA
(412) 471-9427 |
Antares
Beaverton, OR
(503) 641-3962 |
Cadence Design Systems
San Jose, CA
(408) 943-1234 |
CAD-Migos
Redwood City, CA
(415) 369-5853 |
CAST
Pomona, NY
(914) 354-4945 |
Chronology
Redmond, WA
(206) 869-4227 |
Cooper & Chyan Technology
Cupertino, CA
(408) 366-6966 |
Crosspoint Solutions
Milpitas, CA
(408) 988-1584 |
Data I/O
Redmond, WA
(206) 881-6444 |
Dynamic Soft Analysis
Pittsburgh, PA
(412) 683-0161 |
Escalade
Santa Clara, CA
408-654-1627 |
Exemplar
Alameda, CA
510-337-3700 |
Frontline Design Automation
San Jose, CA
(408) 456-0222 |
Hantro Products
Oulu, Finland
358-81-551-4382 |
Harris EDA
Fishers, NY
(716) 924-9303 |
HP-EEsof
Westlake Village, CA
(818) 879-6440 |
HyperLynx
Redmond, WA
(206) 869-2320 |
IMP
San Jose, CA
(408) 434-1281 |
Interactive Image Technologies
Toronto, ON, Canada
(416) 977-5550 |
Intergraph Electronics
Huntsville, AL
(205) 730-8200 |
InterHDL
Los Altos, CA
(415) 428-4200 |
Intusoft
San Pedro, CA
(310) 833-0710 |
IST
Danville, CA
(510) 736-2302 |
Ivex Design
Beaverton, OR
(503) 531-3555 |
Mentor Graphics
Wilsonville, OR
(503) 685-7000 |
Meta-Software
Campbell, CA
(408) 369-5484 |
MicroSim
Irvine, CA
(714) 770-3022 |
MINC
Colorado Springs, CO
(719) 590-1155 |
Model Technology
Beaverton, OR
(503) 641-1340 |
OrCAD
Beaverton, OR
(503) 671-9501 |
PADS Software
Marlborough, MA
(508) 485-7171 |
Protel Technology
Santa Clara, CA
(408) 243-8143 |
QuickLogic
Santa Clara, CA
(408) 987-2000 |
Router Solutions
Newport Beach, CA
(714) 721-1017 |
Sage EDA
Germantown, MD
(301) 540-6280 |
Simucad
Union City, CA
(510) 487-9700 |
Spectrum Software
Sunnyvale, CA
(408) 438-4387 |
SynaptiCAD
Blacksburg, VA
(703) 953-3390 |
Synplicity
Mountain View, CA
(415) 961-4962 |
Tanner Research
Pasadena, CA
(818) 792-3000 |
Topdown Design Systems
Nashua, NH
(603) 888-8811 |
Viewlogic Systems
Marlborough, MA
(508) 480-0881 |
Wellspring Solutions
Sutton, MA
(508) 865-7271 |
Xilinx
San Jose, CA
(408) 559-7778 |
Zuken-Redac
Santa Clara, CA
(408) 562-0177 |
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