Interactive design rule checking is provided, as well as the more conventional batch-mode checking of physical layouts. Arbitrary angles are supported in physical geometry. Properties can be assigned to objects, and the property setting mechanism can be used to modify the geometry of objects.

A simple, non-lisp scripting language and interpreter is provided, with a debugging window that allows single stepping, breakpoint setting, and variable tracing to facilitate script development. A large collection of interface functions is provided, which enables the user to automate many tedious layout functions. Scripts can be executed through a "user" menu, by clicking on a label in the layout, or by clicking on an anchor in the HTML-based help viewer.

Xic provides an extensive help system and on-line documentation. The system is intended to by customized by the user, as the file formats involved are simple and well documented. Scripts can be executed, files loaded into Xic for editing, or simulation runs initiated by WRspice by simply clicking anchors in the viewer. This provides a very powerful documentation tool to the Xic user.

Xic provides netlist and parametric extraction and verification. Xic also provides a built-in partitioning editor for the FastCap and FastHenry programs for three-dimensional R/L/C extraction, as well as a simplified interface to these programs.

Xic is multi-lingual, and will read and write files in GDSII, OASIS, CIF, CGX, and the native format. Any of these file types can be read into Xic without prior knowledge of what they contain - Xic will add layers, etc., as needed. A single, text-mode technology file provides all of the technology-specific information used by Xic. Most of the attributes in the technology file can be set from within Xic, and a new or updated technology file can be generated with a mouse click.

WRspice works seamlessly with the Xic graphical front-end for point-and-click schematic layout and simulation control, though WRspice is highly effective as a stand-alone tool. simulator. The device library includes the latest BSIM MOS models, and SOI models from Berkeley and elsewhere.

New! Jspice3 is free!
Jspice3 has been superseded by WRspice, and is obsolete and no longer under development. The last release, version 2.5, is now available in the free software archive.

Caveats

• Jspice3 does not support Microsoft Windows. The code is supplied as a tarball that you must compile and run on a unix-like system. However, it may be possible to build Jspice3 using Cygwin with X-libraries, and run using a PC X-server.
• It is not possible to provide a demo.
• The program is supplied "as is" with no guaranteed support.
• This is intended for students and experimenters.

Contact Whiteley Research for more information, and for

• Custom Tool and Feature Development
• Device Model Development

The FreeBSD operating system is a highly reliable and high-performance Unix for hardware based on the Intel processor family and clones. It is an augmentation of Berkeley BSD-4.4 Unix, amply supported with thousands applications, both commercial and public domain (including applications intended for Linux). The operating system has proven reliable in some of the most demanding network server applications, and has become the choice of many service providers and high-traffic web sites. For years, both of our sites, at two different ISP's, were "powered by FreeBSD".

While maintaining high reliability, it is reasonably up-to-date with respect to features and functionality. FreeBSD is the main development platform for all Whiteley Research products.

Linux, another Unix-compatible operating system, is also an effective and popular choice. The Linux distributions generally have more support for non-standard hardware, and provide the latest versions of popular software packages "out of the box". Linux is also considered to be easier for a newcomer to Unix to use and maintain. In short, Linux is more of a "desktop" system, whereas FreeBSD is more of a "server" system, but the line of separation is rather faint.

We have, however, encountered a numerical issue in x86 glibc-based Linux which may affect the results of programs ported from other operating systems. This is a difference from traditional Unix behavior and not a bug. This does not affect our products, and Whiteley Research unreservedly supports the major Linux distributions.

When equipping a work group for integrated circuit design, a high-end Intel/AMD system with high resolution graphics and monitor running FreeBSD or Linux has advantages over a proprietary workstation, beyond lower cost. Flexibility is a main consideration, including hardware compatibility with other operating systems, which enhances the system's utility. Raw performance can be equivalent to or better than all but the most expensive, top-of-the-line proprietary workstations. If the hardware breaks, repairs are inexpensive and may entail only a trip to the local electronics store. The initial purchase avoids the negotiation and uncertainty of dealing with workstation vendors' sales organizations and resellers.

How can a public domain operating system be "better" than an operating system supplied by a workstation vendor? Primarily because a large community of Unix experts, many of whom have worked on the Unix operating system for years, is connected into vast workgroups over the internet. These people have organized themselves into highly effective teams, motivated to produce the "best" operating system, bar none. The competition between the different projects, (e.g., FreeBSD and Linux) further accelerates progress. Since all source code is released to the public, the best new ideas migrate quickly. All the wealth of Microsoft could not buy this talent pool. These operating systems, FreeBSD and Linux, represent (arguably) the state-of-the-art in general-purpose operating system technology and (in the case of BSD) reliability. Graphical user interface technology for these operating systems (e.g., the GNOME and KDE projects) is advancing rapidly, but as it stands, Unix/Linux is not for the casual user or computerphobe. The Apple OS-X operating system is actually FreeBSD, with a proprietary graphical user interface. Persistent Internet rumors allege that Microsoft borrowed heavily from FreeBSD for the networking code in Windows. Thus, this technology is slowly working its way into the mainstream.

At present, the proverbial fly-in-the-ointment is compatibility. Some commercial software is not supplied in versions compatible with FreeBSD (or Linux, FreeBSD will run Linux software). Companies which require that software have no choice but to buy the recommended workstation, and probably hire a technician to keep it running. Whiteley Research will never force customers into buying expensive hardware.