1 2 First Previous 21 Replies Latest reply on Feb 10, 2014 7:01 AM by kbak




      I watched the webinar about Design Reuse, it was not 100% clear to me this had to be a Schematic driven function, but it does seem that to be the case.


      Can design reuse be used with a netlist driven design (Orcad Capture netlist output) or not?

      I have tried many attempts to get this to work with a design with major less than acceptable results.


      I take it thee needs to be set up in a schematic in DxDesigner for this to work correctly?




        • 1. Re: Design-Reuse

          It has been a while since I've used reuse but I definitely didn't use DxD when i did it.  I was working with Logic and Layout.


          As I recall, you set up the reuse file (*.reu) in Layout.  Then in Layout you select the parts for the next reuse, select 'ECO mode' and then select 'Add Reuse' (I might have that sequence backwards, it's been almost two years since I last used it).


          I expect the part selection for the next reuse block is easier with cross probing, but you should be able to do it completely in Layout (i.e. with a netlist input).

          • 2. Re: Design-Reuse

            OK well I tried with ECO mode and many other variations.

            When you use make like reuse it does nt even come anywhere close to reproducing another like circuit.

            I would almost have to say it is absolutely useless.

            Unless I am missing something simple this thng does not work at all. Yes it picks a bunch of parts

            but most are not related to a particular common circuit.

            • 3. Re: Design-Reuse

              One of the unique benefits of PADS' Physical Design Reuse is that it is schematic independent.  It can be used strictly with PADS Layout - no matter what front-end tool you use!  Of course, if you have DxDesigner or PADS Logic, you have the added benefit of being able to use the native cross-probing to help with PDR.


              For those of you who have not viewed this on-demand webinar, you can find it at http://www.mentor.com/pcb/multimedia/improve-product-quality-and-designer-productivity-with-design-reuse-in-pads


              A white paper on Physical Design Reuse is at http://www.mentor.com/pcb/resources/overview/physical-design-reuse-in-pads-how-to-leverage-corporate-ip-to-increase-efficiency-in-pcb-design-2a7ce62d-1085-4adb-a646-ecabd5530add



              • 4. Re: Design-Reuse

                Hi Jim,

                Well after viewign the webinar, like I said it seemed easy.

                However there must be some other set up I'm missing or was not shown in webinar.

                Or do I need to review this whitepaper.

                Becuase bottom line from what I am seeing this does not produce common circuits at all.



                • 5. Re: Design-Reuse

                  It is not a requirement that you are cross-probing with DxDesigner or Logic while performing a Make Like Reuse, but it does make things work much better.  When you are cross-probing this allows you to quickly and easily pre-select the components from the schematic sheet that you would like to use in the Make Like Reuse. This selection prevents components, particularly discretes, from another channel from being included in the Make Like Reuse. The system is looking for parts that are electrically correct, not necessarily of the same ref des sequence. You might end up with an R101 and R202 in the same Reuse, rather than R101 in channel one and R202 in channel two. That pre-selection helps to ensure that the proper components are being picked for the assembled reuse.


                  The Make Like Reuse is found under the Design toolbar. This is the command that attempts to use the existing parts in your design.  There is a separate command in the ECO toolbar called Make Reuse.  This will read the contents of a reuse file and add those parts and its associated routing on the fly, it does not assemble the reuse from any existing parts in the design.


                  In order for Make Like Reuse to work properly you need to have a set of parts in which the Part type and PCB decals match those defined in the reuse definition, the pin connectivity must match, net names can be different, but the pin-to-pin connectivity must match between the available parts in the design and the reuse file definition. In some cases the value and tolerance differences can trip up a Make Like Reuse from completing, however, the modeless command RV can toggle the value and tolerance comparison off so those differences are ignored.



                  • 6. Re: Design-Reuse


                    OK I read the white paper and no new information was there. I made a reuse just as described.

                    Then selected reuse & did a make like reuse.

                    The selections of parts was not even close to producing another duplicate circuit.

                    The schematic has been set up with Rf Des series such that Circuit 1 all start with 101 R101 C101 etc.

                    and so next is R201, C201 etc.

                    This thing is pulling in parts that are not even connected to the second or third circuit et.

                    I believe I have et all the criteria explained o make this work?

                    However it does not function as shown in webinar or described in white paper.


                    • 7. Re: Design-Reuse

                      Hi Bill,

                      Well I am trying to have it use the existing parts in the design, so I have use it without using he ECO mode also.

                      Bottom line it is pulling parts and trying to make a circuit that is not representing any of the common circuits.

                      I made sure all the part types & decals are identical.

                      It is pulling those parts just not he ones that are conneced to the common circuits.\


                      • 8. Re: Design-Reuse

                        The best way to use reuse is to make one circuit, select the components and make a reuse. Then you select the second circuit of components  And use the toolbar make like reuse. This will either make the second circuit look like the first circuit or give you a text file why they are not the same. The other option to select a reuse and then use make reuse which does not always work since parts may have the same signal names on the pins and the reuse does not know which one to use.


                        Cross probing from the  schematic to the pcb file works even better.




                        Lenny Alwxman

                        • 9. Re: Design-Reuse
                          David Ricketts

                          When it works, PDR is amazing. But it has serious limitations, an obscure option, and a cryptic error report.


                          It does not require the schematic, but having it provides the advantage of making it easy to select the exact group of parts you want to use. Since you're using OrCAD like I do, here's what to do. Import it directly into Logic. Ignore all of the error messages. You'll be able to link to the PCB, and you get cross-probing. You can't use it for ECO changes or back-annotation, but it's a great tool to help with the layout. More on this later.


                          There's two modes for PDR, ECO and non-ECO. Below, I describe the non-ECO mode, selected from the Design Toolbar, useful for creating one channel, then repeating it as many times as you need within the design. The ECO mode is useful too, but it's restricted by requiring the same layer stackup. It will add parts to the PCB not in the schematic, and you're required to resolve this any way you can. I can discuss this more if you want at a later time.


                          Here's the big limitation of PDR. The parts and connections (not the net names, but the pattern in which they connect) of every channel must match 100%. If there's one part too few, PDR won't work. If the Value and Tolerance attributes are different, PDR won't work (except that a few months ago, after using PDR for years, I learned of the modeless command RV that turns off checking those attributes. It's been there for years, but I never read or learned about it.)


                          So first, identify the channels, and make sure they meet the criteria for PDR. If, for a digital example, on one channel, a resistor is used as a pullup, and in the next the corresponding resistor is used as a pulldown, common for identifying channels, PDR won't work. You have to create the first reuse, the seed as it were, with only the common parts, and you have to place the outlying parts later. It's also common that, on otherwise identical analog channels, different resistor values are used for different gains, so for this case, you need to use the RV option. The drawback for using RV is that PDR can't identify parallel parts, so if you have 2 or more differently valued decoupling caps on a power pin, the smaller value won't always end up as the closest part.


                          There's an unrestricted use of PDR that works, but only rarely, and I don't recommend it. That entails creating the first channel, making then selecting a reuse, then picking Make Like Reuse. It sorts through all of the parts on the PCB. To me, it's a crapshoot to make it work like you want, and doesn't deal correctly with parallel parts like decoupling caps. I use the restricted method described below.


                          When I'm doing placement, PDR is a great tool to make sure the parts fit. Place the first channel, don't worry about routing, and create a reuse, saving it to a file. Then select the parts for the 2nd channel. Here's where a cross-linked schematic is helpful. Pick them on the schematic, and they're ready on the PCB. Select Make Like Reuse, select the file name you just made, and the parts should organize as a new reuse, and placement can continue. Doing PDR this early makes it a little easier to identify problems that keep it from working. Once in a while, you'll find schematic errors that prevent it from working, and they're always best caught early.


                          Later on, after knowing everything fits and the placement is approved, I do the fine-tuning on the first channel. Of course, I always forget to break the reuse before trying to move a part, so be sure to do that. Fine tune the placement and route the channel. Place the ref des attributes too, because PDR now remembers their location (I don't know when that started). Create a Reuse. Filter for components only, and select the parts in the next channel, and pick Make Like Reuse like before. It should work. Don't tell your boss about PDR, and let then marvel at all the hard work you must have done.


                          But many times, too many in my opinion, making the new channel doesn't work. Or sometimes, several will work, then there's one that doesn't. You get a very lengthy report, and if you're patient, you might be able to find what's wrong. Component count is my most common reason. If there's too many parts in your selection, I'm pretty sure it still works, but it won't if there's too few. The biggest error that won't appear in the report is that one of more of the selected components is glued. So make sure they aren't glued, and also not part of another PDR.


                          Good luck, and keep trying because it is worth it.




                          • 10. Re: Design-Reuse


                            Well I really think you made a very key phrase.

                            "But has serious limitations"

                            Key word being seroius.

                            I have circuits.

                            As far as I can tell they are identical.

                            ALL values are the same all decals are the same.

                            It is a simple circuit.

                            A detector, 1 so8, 1 ssop16 and a few R's & C's.


                            I select all of the parts I want in the reuse.

                            I then right click and make reuse. Save it off.

                            I then select one of the parts within the reuse & rt click pic Select Reuse.

                            Then rt click to get Make Like Reuse

                            What happens next it take most of the parts (common decals) from the other common cicuits not part of the identical 10 circuits.

                            It absolutely does not pull most of the parts form the 10 circuit group of parts.

                            IMHO this tool really does not work at all.


                            I had a glimmer of hope thinking in your description that I had to select all of the parts in the second circuit first then select make like reuse.

                            However not the case those commands are greyed out.

                            You need to select one of the parts within your reuse, then rt click and then make like reuse will be selectable.

                            But again these circuits are identical and the results are not even close to using the appropriate set of parts.


                            It really seems to me that there a real requirement to have the schematic tie in to possibly make this actually work???

                            You say no but I don't see it as having a chance of working without, at lest with everything I've tried so far.

                            • 11. Re: Design-Reuse

                              You need to use the suggestion I made previously. The probelm with what you are doing is if you have a part like a decoupling cap that has the same signal names as other decoupling cpas the software has no way to determine which cap goes with which circuit. Make a reuse then selct the componets for the second reuse and use make like reuse from teh toolbar. I do this all the time and as long as the parts are the same and the nets connect the same then  it works great.

                              • 12. Re: Design-Reuse



                                The  key to getting the desired components is to use the toolbar as Leonard describes. Don't use the RMB.



                                • 13. Re: Design-Reuse

                                  Sometimes I get a circuits where we put a zero ohm or other small value resistor in series with the supply pins (before the cap). In these cases the decoupling caps are isolated from the others on the board so PDR works pretty well using the RMB method.



                                  • 14. Re: Design-Reuse

                                    OK thanks finally, the key word was toolbar.

                                    I did not pick up on Toolbar vs RMB menu.

                                    I would have thought command same.

                                    I scaled it back to picking 3 parts in reuse, and yes if you use the toolbar icon for make like with all the parts selected on the second circuit

                                    it will place on cursor the parts same as first circuit.

                                    But if parts are scattered all over and not somewhat grouped already having the schematic there to cross probe is invaluable for this to work easily.

                                    Thank You All for the help

                                    1 2 First Previous