Reusing existing circuitry is as simple as placing a Device SheetSymbol Theybundle nets and buses together so the structural schematic sheets canbe kept clean and simple.įigure3. SignalHarnesses are an excellent partner for Device Sheets as well. In no time at all I had added USB and touchscreen hardware into mydesign ( Figure 3, below ), usingthe Place Device Sheet Symbol command and placing the appropriateDevice Sheet Symbols from the Select Device Sheet dialog. I noticedthat the supplied Altium Device Sheets were already hooked in, so Iadded another link to a suitable location on our network, where I couldstart copying schematics of our own reuseable sections of designs. To let Altium Designer know where my reusable schematics, or DeviceSheets, are stored, I just needed to reference the location in theSchematic ” Device Sheets page of the Preferences dialog. I also learned that while a Device Sheet lets me reuse a chunk ofcircuitry, I could also build a hierarchy of Device Sheets if needed.This is perfect for those situations where there is a larger section tobe reused. I was happy to read thata Device Sheet is actually just a standard schematic sheet, which meansit will be straightforward to take sheets from our existing designs andreuse them as Device Sheets. I then checked the help PDF to learn more. (To view a larged view of this figure, clickhere.) Device Sheets are standard schematics, but because they are placedas a Device Sheet Altium Designer can be configured to show them asread only, and recycled. They were useful on-screen, but I definitely did not wantthem included in the client's PDF!įigure2. I printed the sheet to checkthat the watermarks were not included, but just the circuitry printedas I'd hoped. TheDevice Sheet had interesting watermarks on it, the recycling symbol wasthere again, and also the text, Read Only. I drilled down into one of the Device Sheets on the NanoBoardschematic, the USB in fact, because my design would use the same USBdevice ( Figure 2, below). And byclicking the link in the summary in the Knowledge Center panel, I had aPDF called Using Device Sheets open, ready to guide me. I now knew that a reusable chunk of circuitry was called a DeviceSheet, and it was accessed by placing a Device Sheet Symbol. Pressing F1 ( see in Figure 1 below )as I hovered the mouse over the symbol, I discovered that this was aDevice Sheet Symbol (instead of a standard sheet symbol), which pointsto a Device Sheet, and that Device Sheets are reusable blocks ofcircuitry. One of the first things that caught my eye on the top schematicsheet for the NB2 was the recycling symbol inside some of the sheetsymbols, ahown below: So whenmy snazzy new NanoBoard arrived I had the schematic and board filesopen in Altium Designer as soon as the board itself had been plugged inand powered up. Like any engineer, I'm always curious to see how things work. I can save loads of time andaccelerate that process if I re-use circuitry directly from the DesktopNanoBoard, so it's time to brave the waters of design reuse. My current design has been prototyped on the Desktop NanoBoard, andit's time to move it to a custom board. Well, it's time for this skeptic to put his money where his mouthis. This has always been the deal-breaker inthe past ” how to maintain unique component designations in the newdesign, without resorting to some complex and convoluted naming scheme,like R1_Power_1v2, in the master re-use copy. This must be done without affecting the assignments on the master copy(as that would break rule 1). Since thiscentral resource cannot be edited, the design environment must supportthe ability to update the component designators on each new design. We want everyone in the team to be able to easilyexplore and use all our proven circuits, with all additions and changescontrolled and managed by our formal review process.Ģ. Theschematics must be available for everyone to use, but secure from anyediting. That meant it had to be subject to the standard reviewand triple-check sign-off process.įor design reuse to work, there are a couple of fundamental challengesthat must be solved.ġ. So I'd have to say that I was skeptical when I read statements aboutdesign reuse in Altium Designer – “I'll believe that when I see it”were my exact words.Įveryone in the team was already practicing design re-use, we werecopying and pasting sections of existing designs ” like standard commsor power supply sub-circuits ” into our current projects.īut there was no integrity in the copied design, because any numberof mistakes could be made during the copy/paste process, and theengineer could and would modify the circuit to suit their idea of agood circuit. And if youwere to push me to take a position, I used to doubt it would ever befound. The ability to reuse existing sections of designs islike the quest for the holy grail in our design team – something wevalue highly and dream of finding, but have yet to discover.
0 Comments
Leave a Reply. |
Details
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |