I've performed some simple signal propogation/loading analysis with Excel and another engineer later reproduced the findings with PSPICE. I've also performed a 2D field analysis using the iterative calculation functionality of Excel. The graphic representation was nice. A background heavy in reliability engineering has taught me the value of the spreadsheet as a tool for engineering analysis, starting with an early version of Lotus 1-2-3 (1985 or so). More recent experience has pulled on that knowledge to use it heavily in production yield analysis and machine/process throughput models. Learning the power tools, especially the analysis package and the VB macro language, has made Excel my most-used tool. John Thomas -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Ray Anderson Sent: Monday, September 27, 2004 10:45 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Using general purpose computer tools to solve SI problems Engineers quite often utilize specialized software to solve specialized problems in their work. A few general examples of these tools might be:=20 spice simulators, field solvers, model generators, netlist generators etc. The list goes on and on. As has been discussed recently, sometimes more general purpose computing tools such as spreadsheets can be used to advantage to solve engineering problems if applied appropriately. In the example of the spreadsheet, even though the most common use of the tool is to automate 'book keeping' functions, beneath the hood lives a powerful math engine and graphics interface. Quite often those intrinsic qualities of the tool can be utilized in imaginative ways to solve engineering problems that would otherwise require specialized software that might not be available to the user. The non-availability might be due to the fact that the type of problem to be solved is uncommon enough that acquisition of a special tool isn't cost effective, that a commercial tool is cost prohibitive, or perhaps that a tool designed to solve some particular problem just does not exist. I was wondering if list members might share (the concept, not necessarily the tool) examples of innovative uses of general purpose computing tools to solve problems that they've either used or seen used. To start off, I'll volunteer the use of an Excel spreadsheet to recursively calculate the DC drop on a PCB from the VRM to the core power pins of a CPU packaged in a BGA package accounting for PCB cutouts, swiss-cheesing effects of anti-vias etc. There have recently become available elegant commercial tools that very accurately deal with this problem, however, in the past the problem of determining and visualizing these distributed voltage drops accurately (or even inaccurately) has been problematic. One other example, although not strictly SI related, is a shareware application a friend of mine developed called MultiNEC. Based on the Excel spreadsheet and utilizing the VB macro capability of that tool, it performs pre and post processing functions for NEC (Numerical Electromagnetic Code) simulations. It allows antenna geometries to be defined and then it generates the appropriate input decks for the simulator. It also analyzes and graphically plots the results from the NEC solve engine. Interface from the spreadsheet to the NEC simulator is seamless. There are many other capabilities integrated as well which all depend on the spreadsheet framework. I for one, would be interested in learning of other interesting applications of general purpose computing tools that engineers have come up with to deal with SI and other engineering problems. If anyone actually wants to share a particular tool that would be great, but just the general knowledge of what has been or can be done may provide the impetus for others to develop their own applications. -Ray Anderson ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: =20 //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu =20 ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu