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CircuitMaker 2000 The Virtual Electronics Lab If you thought that access to the latest printed circuit board design and circuit simulation tools was restricted to big companies with big budgets, think again! This review looks at CircuitMaker 2000, a complete design solution aimed at small to mediumsized projects and users. By PETER SMITH CircuitMaker 2000 is a new release of a mature product developed by the US company MicroCode Engineering. Micro­ Code have a 10-year history in the development of affordable electronic design automation (EDA) software. MicroCode Engineering were recently acquired by Protel International, a name that most of us are familiar with (we reviewed Protel 99 in the January 2000 issue). The upshot is that CircuitMaker is now being sold and supported in Australia. 26  Silicon Chip The CircuitMaker 2000 package includes schematic capture, analog and digital circuit simulation and PCB layout software and is offered in both “Standard” and “Professional” editions. We reviewed the Professional edition but we’ll note the differences as we look at each of the major functions. Let’s jump right in … Schematic capture The first stage in bringing a design to reality is getting the schematic down on “paper”. CircuitMaker 2000’s schematic editing environment is based around the familiar Windows-style interface, and is one of the easiest-to-use I have seen. A comprehensive library of component symbols is directly accessible from a browser panel on the left side of the workspace (see Fig.1). A handy feature allows assignment of shortcut keys to the most common components in a circuit, which means that once you’ve found the symbol you want the first time, you don’t have to waste time searching for it again. If you need a symbol that’s not in the library (and that shouldn’t be too often), you can use the inbuilt Symbol Editor to edit an existing symbol or create a new one from scratch (see Fig.2). Unlike the schematic-editing environment, I think that a newcomer would find the Symbol Editor quite awkward and decidedly non-intuitive. There is no access to on-line help while the Symbol Editor is open, either. Ho-hum, it really does provide everything needed to edit or create both simple and complex symbols, with the ability to link all kinds of simulation data (see “Circuit simulation” below). If you’d like to see the complete list of devices included with CircuitMaker 2000, you can download the Device Library Guide (in Adobe PDF format) from http://www.circuitmaker.com/ downloads/libraries.htm Wiring it all together is a piece of cake. Click on a device pin or a wire, drag the cursor to the target connection point and release, and Circuit­Maker automatically routes the wire. And you don’t have to precisely place the wire start and end points, as CircuitMaker automatically captures the cursor when it is moved close to any node (like a device pin). As you’d expect, wires can be routed manually if desired. A large cursor Fig.1: finding the right symbol and wiring it up is a simple task in the Schematic Editor. Fig.2: if you need to create a new symbol (or change an old one), you do it in the Symbol Editor. Put on a pot of coffee if it’s your first attempt, though . . . makes it easy to line everything up neatly – very useful in this package as the “snap to grid” option snaps symbols to a grid but not wires. Editing your masterpiece is very straightforward. Symbols can be mov­ed around the workspace with connecting wires intact, as they are automatically “rubberbanded”. Wires can be lengthened, shortened or deleted with little more that a right mouse click, or moved intact to a new position by clicking and dragging. Precise alignment of objects can be achieved by “nudging” them into position with the arrow keys. Circuit simulation With the schematic completed, you can move directly to PCB layout and physical prototype. But what if you could test (optimise, demonstrate) your design first? CircuitMaker 2000 includes a powerful analog and digital circuit simulator that is tightly integrated with the schematic editor. Most symbols in the library are linked to pre-defined simuAugust 2000  27 Fig.3: digital simulation is easy to drive and the results are plain to see. Here we follow the condition of five points in the circuit (TP1 to TP6) with the logic analyser. Simple breakpoints and single or multiple-cycle stepping lets you slow things down to human level. lation information (called “models”), so once your circuit is complete, you can begin simulation with very little setup. Over 4000 device models are included in the Standard edition, and 6000 in the Profession edition. Two independent simulation modes are provided. For analog or mixed analog and digital circuits, Circuit­Maker 2000 includes an enhanced SPICE 3f5 and XSPICE compatible simulator. SPICE (a classical computer acronym meaning “Simulation Program with Integrated Circuit Emphasis”) is the industry-standard method for circuit simulation. The second mode supports digital simulation only and is of proprietary design. Why? Well, the CircuitMaker people have been able to incorporate some very nice interactive features in this mode, making it a powerful instructional tool. Lets look at this mode first. Digital simulation Any complete digital circuit includes some kind of clock source, so the first step is to connect either the logic pulser or logic sequencer from CircuitMaker’s “instrument” devices. Next, test points can be connected to each node that we would like to examine (instruments and test points are placed from the component browser and connected just like regular components). Finally, clicking on the “run” button launches a “real-time” simulation of the circuit, with waveforms for each test point displayable either in split-screen or full-screen mode (see Fig.3). Fig.4: you can have your tudents pulling their hair out with the digital simulator’s Device Faults function. 28  Silicon Chip Digital simulation includes a number of major features that make it ideal for educational purposes. Firstly, a built-in logic probe enables instant display of the logic state (low, high or high-impedance) of any point in the circuit, much like using a real probe on a real prototype. Secondly, a trace mode can display the logic state of every wire in the circuit by changing its colour to either blue, red or green to indicate a low, high or high-impedance state respectively. Another useful feature allows faults to be introduced into the circuit for a real “hands-on” learning experience (see Fig.4). And lastly, CircuitMaker 2000 includes a handful of “animated” components. Devices like 7-segment displays, buzzers and LEDs function just like their real-world counterparts. And there’s even a launchable rocket! (see Fig.5). Analog simulation A whole host of analyses can be performed on both analog and mixed analog and digital circuits using the SPICE simulator (see Fig.6). These include DC Analysis, AC Analysis, DC Operating Point, Transient Analysis, Parameter Sweep and Fourier Analysis. The Professional edition adds Transfer Function, Noise, Temperature Sweep, Monte Carlo and Impedance Plot analyses. A variety of virtual instruments are available for generating stimuli and viewing the simulation results. These include an Oscilloscope, Digital Multimeter, Bode Plotter, Curve Tracer, Signal Generator, Data Sequencer, Logic Analyser, Logic Probe and Logic Pulser. For my money, the stand-out part of the CircuitMaker 2000 package lies right here in its analog simulation capabilities. Even a beginner to simulation can quickly get meaningful test results. A probe tool allows instant measurement of voltage, current and power almost anywhere in the circuit. Just point and click and the results are immediately displayed on the selected instrument for analysis. Conversely, some other packages insist that you define test points and connect instruments before the simulation even begins. Sensible default simulation parameters, automatic waveform scaling and zooming and many other handy little shortcuts go together to make this simulator a very useful tool indeed. PC board layout “TraxMaker” is the name of the PCB layout software included with Circuit­ Maker 2000. Although it’s a separate module, it is closely integrated with the schematic editing software. To transfer information from the schematic editor to TraxMaker it’s just a matter of clicking on the “Export PCB Netlist” button. To make life even easier, you can have TraxMaker position all components on your board ready for placement and routing (see Fig.8). A handy addition to the Professional edition also allows direct import of Protel Advanced PCB2 and Advanced PCB3 ASCII files. Manual track placement and editing are a breeze and have a familiar feel. For example, a right mouse click provides easy access to the most commonly used functions, as do shortcut keys and menu bar buttons – just like the schematic editor! Individual tracks, groups of tracks or the entire board can be routed automatically if desired. The Professional edition includes a more sophisticated autorouter (call a “ripup and retry” maze autorouter) which has a higher completion rate and more efficient routing (meaning less vias). All routing is grid-based, with a maximum resolution of .025mm (.001 inch). Up to eight copper layers are supported (six signal layers and two power planes) as well as solder and paste masks, keep out layer and reference layer – more than enough for most small to medium-sized projects. TraxMaker includes a comprehensive component footprint library. And if you can’t find what you want in the library (see Fig.10), editing or expanding it is a cinch. New footprints are drawn directly in the PCB editor space using standard primitives like pads, tracks and text, then grouped and included in the library in a single step. Great! Fig.5: interactive devices make your digital simulations come to life! This example shows switches, a piezo buzzer and a LED display that really work. Fig.6: CircuitMaker’s analog simulation is first rate. Here we examine the voltage at four nodes in an astable multivibrator circuit. Checking your work Before shipping your design off to be made, you can be sure that it’s right (at least electrically!) by running the Design Rules Checker (see Fig.11). It looks for basic problems in your layout like open circuit nets and clearance violations (tracks/pads short circuited or too close together) and generates a detailed report. In common with all PCB layout software, TraxMaker generates industry-standard output file formats (Gerber and Excellon) that will be acceptable to all PCB manufacturers. CircuitMaker 2000 Professional edition includes an additional piece of software called TraxCAM PRO, a fully featured Gerber viewer and ediAugust 2000  29 Fig.7a (left & Fig.7b (above): setting up two of CircuitMaker’s instruments. Fig.8: two mouse clicks gets your design into the PCB layout software. tor. TraxCAM PRO allows you to query, edit, print and add copper pours to your design prior to manufacture. Last word Overall, we were impressed with the simplicity of use and value for money in this package. Its circuit simulation capabilities alone would make it an attractive proposition for institutions involved in electronics training. Like more information? Fig.9: editing a single-sided design in TraxMaker, the PCB layout module. In fact, this is the PCB from the 40V 1A power supply project described in the August 2000 issue. The design was imported from a Protel Advanced PCB file (ASCII format). Fig.10: TraxMaker’s footprint library is comprehensive and easy to use. 30  Silicon Chip Loads of information and a downloadable demo is available from the CircuitMaker web site at http://www. circuitmaker.com Local telephone support is available on 1800 676 684 or e-mail aust-support<at>circuitmaker.com The pricing details are as follows: (1) Standard Edition $645 (includes GST); (2) Professional Edition $1195 (includes GST). For sales enquires phone 1800 030 949 or e-mail austSC sales<at>circuitmaker.com Fig.11: a Design Rules Checker allows final checks on your work before sending it to manufacturing.