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Electronics Forum / CAD / April 2008Survey: FPGA PCB layout
Does anybody out there have a good methodology for determining your optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? The brute force method is fairly maddening. I'd be curious to hear if anybody has any 'tricks of the trade' here. Also, just out of curiosity, how many of you do your own PCB layout, versus farming it out? It would certainly save us a lot of money to buy the tools and do it ourselves, but it seems like laying out a board out well requires quite a bit of experience, especially a 6-8 layer board with high pin count FPGA's. We're just setting up a hardware shop here, and although I've been doing FPGA and board schematics design for a while, it's always been at a larger company with resources to farm the layout out, and we never did anything high-speed to really worry about the board layout too much. Thanks in advance for your opinions. Dave >Does anybody out there have a good methodology for determining your >optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 14 lines] > >Dave Sure wish there was a slick way of doing FPGA pinouts. I usually use graph paper and figure out the FPGA pinout to other parts to minimize routing snarls. I do pcb layouts on my own and other folks designs. Our boards have high-speed routing, switching power supplies, and high-gain analog stuff; sometimes all on the same board. Unless the service bureau has someone who understands how to lay out such circuitry and place sensitive analog stuff near digital junk, it is more trouble to farm out than do it yourself if you want the board to work on the first cut. Doing your own layout will take a lot of learning to master the PCB layout program and what your board vendor can handle. It will take 5 to 10 complicated boards to become mildly proficient at layout. I don't know about saving cost. Your time may be better spent doing other activities rather than learning about layout and doing the layouts. The upside to doing your own layout - you control the whole design from start to finish. If you have a challenging layout, you'll have a much higher probability of having a working board on the first try which has hidden savings (getting to market earlier <- less troubleshooting + less respins). --- Mark >> Does anybody out there have a good methodology for determining your >> optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 26 lines] > out than do it yourself if you want the board to work on the first > cut. Or find a good layouter and develop a long-term business relationship. My layouter knows just from looking at a schematic which areas are critical. He's a lot older than I am and that is probably one of the reasons why his stuff works without much assistance from me. Nothing can replace a few decades of experience. > Doing your own layout will take a lot of learning to master the PCB > layout program and what your board vendor can handle. It will take 5 > to 10 complicated boards to become mildly proficient at layout. I > don't know about saving cost. Your time may be better spent doing > other activities rather than learning about layout and doing the > layouts. ... Yep, that's why I usually do not do my own layouts. Occassionally I route a small portion of a circuit and send that to my layouter. No DRC or anything, just to show him how I'd like it done. > ... The upside to doing your own layout - you control the whole > design from start to finish. If you have a challenging layout, you'll [quoted text clipped - 4 lines] > --- > Mark  SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. >>> Does anybody out there have a good methodology for determining your >>> optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 52 lines] >> --- >> Mark I agree with Joerg. Good high speed or mixed signal PCB layout is a career choice, and we electrical engineers already chose our career. A good layout requires someone who understands not just the software package, but the details of how the manufacturing operation is going to proceed, what the limits of the processes are, what the assembly operations require of the board, and is anal about things like footprint libraries and solder mask clearances and a thousand other details that I'm only partially aware of. The more complex your design, the more critical these things become. I have two good local outfits for farming out boards. For complex stuff, they know I'll come to their place and sit next to the designer for a good bit of the initial placement. While we are doing placement, we are also discussing critical nets, routing paths, layer usage, etc. That gives us direct face to face communication and avoids spending lots of time trying to write/draw everything in gory detail (which gets ignored or misunderstood a lot of the time). That investment pays big dividends in schedule and board performance. Don't be fooled by the relatively low cost of the software. That's not where the big costs are. I once laid off my entire PCB layout department and sent all the work outside, because although my employees all knew how to use the software, none of them could tell me what their completion date would be, or how many hours it would take, and they certainly weren't interested in meeting schedules. The outside sources would commit to a cost and a delivery date. And we already knew they could meet our performance objectives. Fixed price contracts are great motivators. Missing an engineering test window, or slipping a production schedule because of a layout delay can be enormously expensive. Of course, if I had let my engineers do their own layouts, the motivation would have been present, but the technical proficiency would not. How proficient can anyone become if they only do layout a few times a year? Also, on many projects engineers use the layout period for other important things like documentation, test procedures, writing test code, etc. Doing your own layout serializes these tasks and will stretch your schedule. So my advice is to keep doing what you have been doing. Its far more likely that its the cheapest approach, even though you occasionally have to write a big check. Steve > >>> Does anybody out there have a good methodology for determining your > >>> optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 104 lines] > > Steve I tend to agree with the 'farm-it-out' crowd. Unfortunately, my current employer doesn't want to work with my previous layout people, so I've been trying to search for a new partner. I've found plenty of board fab and assembly places, but not so much on the layout. It made me think that the rest of the world did their own layout. The opinions look pretty split from the replies here, maybe it comes down to how many times you do a layout each year, and how much you enjoy that sort of work. I definitely think it's something you have to do fairly often to keep your chops up. Andy, I'd also like to hear more about your pin-swap FPGA design flow - what tools do that? Also curious about any timing issues that have been caught after the pin-swap. Thank you all very much for the info. If any of you find yourself in the Baltimore area, I owe you a crabcake sandwich and a beer. Dave > I tend to agree with the 'farm-it-out' crowd. Unfortunately, my > current employer doesn't want to work with my previous layout people, > so I've been trying to search for a new partner. I've found plenty of > board fab and assembly places, but not so much on the layout. It made Some of the PCB software vendors have lists on their web site of independent consultants and layout houses that use their software. I went on the Mentor site and found zillions of layout people. -Jeff > The opinions > look pretty split from the replies here, maybe it comes down to how > many times you do a layout each year, and how much you enjoy that sort > of work. I definitely think it's something you have to do fairly often > to keep your chops up. I think what you're seeing is that fact that, by sheer volume of products, guys doing relatively low-speed digital stuff completely dominate those doing very low-level analog, RF, microwave, or truly high-speed digital. In the former case, it just doesn't really matter that much how you layout the board. Sure, there are definitely better ways and worse ways, but even up to clock rates pushing 100MHz, for digital stuff I think you can give a guy about an hour of education and he'll be able to make boards work just fine. Another point to keep in mind is that there's a significant difference between being able to design a board well when you're talking relatively small volume production for high-end commercial or military customers where you can afford to just toss in some extra layers and pay for blind or buried vias or tigether tolerances if you're at all unsure of how well your layout skills really are vs. designing a complex board for highly cost-competitive mass-markets. The later requires a lot of skills that are anything but what is commonly taught! (E.g., typically at tech seminars you'll hear people preaching, "throw in a ground plane!" -- an action that saves many an otherwise broken design, but one which might not be possible if your competition has already figured out how to live without one.) I'm a big advocate of giving "technical interviews" to would-be PCB layout guys based on what your needs are. If you're doing, e.g., RF or high-speed digital design, ask them how line impedances change with changes in board and trace dimensions, what near-end and far-end crosstalk look like on a scope, what they think about splitting up ground planes, how they'd route some simple circuits, etc... Usually you can find out pretty quickly what their skills are whether or not they're adequate or if they'd need a bit more hand-holding... which could be fine too, if you have the time and the price is right. > Andy, I'd also like to hear more about your pin-swap FPGA design flow > - what tools do that? It's a common feature in most PCB tools to allow pin (and gate) swapping based on the component's library entry being set up to designate which pins and gates are "swappable." After doing so, most of them will produce a simple ASCII "was-is" text file that list the old pin name and the new one, which can be imported back into a schematic capture program or used to update your FPGA place & route constraints. (PADS will do all this, where Pulsonix unfortunately does pin & gate swapping quite nicely but will only update a Pulsonix schematic "directly" rather than providing you with the option to generate a was-is file.) ---Joel >> The opinions >> look pretty split from the replies here, maybe it comes down to how [quoted text clipped - 9 lines] > rates pushing 100MHz, for digital stuff I think you can give a guy about an > hour of education and he'll be able to make boards work just fine. Not anymore. Part of my daily bread is earned salvaging designs where someone thought "Oh, it's just slow stuff". But it ain't grampa's old SN7400 anymore, today's logic chips are fast. Some like the tiny logic chips swing their outputs within very few nanoseconds. Then some unexpected weirdnesses show up. Everyone thinks it's software but in reality crosstalk has manifested itself. Other times the moment of truth cometh at the EMC lab when a thick forrest shows up on the spectrum analyzer. > Another point to keep in mind is that there's a significant difference between > being able to design a board well when you're talking relatively small volume [quoted text clipped - 7 lines] > one which might not be possible if your competition has already figured out > how to live without one.) And don't split that plane. But yes, often one has to make do with two-layer phenolic. That is often true art. BTW does that little switcher work? [...] SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > Not anymore. Part of my daily bread is earned salvaging designs where > someone thought "Oh, it's just slow stuff". But it ain't grampa's old SN7400 > anymore, today's logic chips are fast. OK, ok, good point. Doesn't someone now have a logic family that's purposely been slowed down due to this "problem?" > And don't split that plane. But yes, often one has to make do with two-layer > phenolic. That is often true art. From Thomas Lee (Stanford) in "Planar Microwave Engineering": In extremely low-cost consumer devices (e.g., toys, pocket radios, etc.), an even less expensive board material is not infrequently encountered. Phenolic is often a caramel brown, typically has an "organical chemical" odor, and is remarkably lossy. Although phenolic is occasionally used for RF toys up to 100MHz, it is totally insuitable for serious applications. It is mentioned here simply to answer the question: "What is that cheap, malodorous board made of?" :-) I know, I know, he's living in an ivory tower a bit, but he is one smart cookie. > BTW does that little switcher work? I've had that board back for about a week, although I haven't actually tested out the switcher yet since the DSP guy isn't interested in working with the new (digital) board until the new RF board comes back (and gets tested) as well, which is still a couple weeks out. (There's this "Big Tester Board" that's needed to test the RF board and said BTB has spent something over a week bouncing around engineering getting tweaked/fixed/etc... we'll be paying a premium to actually get it fabbed in time to start testing RF boards at this point, unfortunately :-( .) I can and probably should just put a dummy load on the switcher, turn it on, and see if there's any obvious problems before the DSP guy starts looking at his clock jitter. Tomorrow sounds like a good day for that... ---Joel >> Not anymore. Part of my daily bread is earned salvaging designs where >> someone thought "Oh, it's just slow stuff". But it ain't grampa's old SN7400 >> anymore, today's logic chips are fast. > > OK, ok, good point. Doesn't someone now have a logic family that's purposely > been slowed down due to this "problem?" There used to be but it's gone. They also had really high threshold voltages and stuff. >> And don't split that plane. But yes, often one has to make do with two-layer >> phenolic. That is often true art. [quoted text clipped - 13 lines] > I know, I know, he's living in an ivory tower a bit, but he is one smart > cookie. Errr, well, those sure sound like ivory tower statements. For some reason all the phenolic I ever used has never smelled. Unless something blew up on there, of course, but then FR4 will also let off a nasty stench. The new stuff looks amazingly similar to FR4, not dark brown. Remarkably lossy? Nah. I have proof to the contrary right here in the garage (if it's still there), a VHF/UHF TV splitter and 60ohm to 240ohm transformer where the UHF part is almost completely done in microstrip. Yes, microstrip on phenolic. There may be a fraction of a dB here and there but on short stretches that hardly matters. Usually those things are for outdoors so it's lacquer coated anyway. Phenolic is somewhat hygroscopic so you have to watch out for moisture. Totally insuitable for serious applications? Oh man. Let's see, what have we here? A 418MHz transmitter, several matching networks, a UHF receiver ... all on phenolic. Sometimes I wish that professors had more nose-to-the-grindstone industry work under the belt. I mean real design work where cost is a big factor. Otherwise they are going to tell students they should use Rogers for just about everything ... >> BTW does that little switcher work? > [quoted text clipped - 9 lines] > the DSP guy starts looking at his clock jitter. Tomorrow sounds like a good > day for that... That would be good. Gives you a head start just in case there is a surprise ;-) SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > Totally insuitable for serious applications? Oh man. Let's see, what > have we here? A 418MHz transmitter, several matching networks, a UHF > receiver ... all on phenolic. Multi ghz RF+matching stuff, analog and some digital will work on an FR4 derivative. > Sometimes I wish that professors had more nose-to-the-grindstone > industry work under the belt. I mean real design work where cost is a > big factor. Otherwise they are going to tell students they should use > Rogers for just about everything ... Don't forget rogers is not perfect , intolerance to flexing and intolerant of poor soldering techniques. > Errr, well, those sure sound like ivory tower statements. For some reason > all the phenolic I ever used has never smelled. Maybe you're missing those receptors in your nose? :-) I've found that phenolic has a much stronger smell than FR-4... not necessarily all that "malodorous" vs. any other common board materials, but definitely a lot more noticeable. > Sometimes I wish that professors had more nose-to-the-grindstone industry > work under the belt. I mean real design work where cost is a big factor. > Otherwise they are going to tell students they should use Rogers for just > about everything ... Yep, that is a problem. Have you been to something like IEEE's MTT-S recently? It really is a different world, and unfortunately the same part of our culture that now says you need a BSEE to be an oscilloscope salesman is, I think, what has made it much more difficult for working engineers to enter academia. Becoming a EE professor is now seen as a career in and of itself, rather to the preclusion of of being a "practicing" engineer where you have significant cost constraints. ---Joel >> Errr, well, those sure sound like ivory tower statements. For some reason >> all the phenolic I ever used has never smelled. [quoted text clipped - 3 lines] > "malodorous" vs. any other common board materials, but definitely a lot more > noticeable. Possibly :-) Just went over to the lab and took a sniff. The really old dark versions might have a wee scent but the newer more light boards don't. The shepherd looked at me quite puzzled when I sniffed the boards. So she took a sniff as well but walked away upon dicovering that it ain't edible. If there were a stench she'd have sneezed. >> Sometimes I wish that professors had more nose-to-the-grindstone industry >> work under the belt. I mean real design work where cost is a big factor. [quoted text clipped - 8 lines] > rather to the preclusion of of being a "practicing" engineer where you have > significant cost constraints. IEEE also needs step onto the real world of engineering, and soon. Else member retention will become a problem. I'd be interested in teaching once I retire but the bureaucratic hurdles are so high that it might have to be in a more private setting, without academic institutions, colleges or schools involved. I am not going to spend thousands on a teaching credential just to appease some bureaucrat. And the students must be motivated, otherwise I won't do it. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > I'd be interested in teaching once I retire but the bureaucratic hurdles > are so high that it might have to be in a more private setting, without > academic institutions, colleges or schools involved. I am not going to > spend thousands on a teaching credential just to appease some > bureaucrat. And the students must be motivated, otherwise I won't do it. Teaching doesn't require much in the way of credentials for university level. Getting on the tenure track is an entirely different matter. If you want to teach, head off to see the dean of your local university/community college, and ask what they need. Not much money, but it still can be a very satisfying experience. -Chuck >> I'd be interested in teaching once I retire but the bureaucratic >> hurdles are so high that it might have to be in a more private [quoted text clipped - 6 lines] > level. > Getting on the tenure track is an entirely different matter. There shouldn't be any tenure in the first place. There is a reason why the tenure concept does not exist in industry. Just my humble opinion. > If you want to teach, head off to see the dean of your local > university/community > college, and ask what they need. Not much money, but it still can be a > very > satisfying experience. Some day I will, when I throttle back design work and money (hopefully) isn't a big issue. It doesn't have to be any ritzy school as long as the audience is motivated and the school isn't a huge driving distance away. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > There shouldn't be any tenure in the first place. There is a reason why the > tenure concept does not exist in industry. Just my humble opinion. Doesn't tenure just mean that you have to screw up particularly badly to get fired? And that even after you officially quit teaching/researching you're generally still allowed to come and play in the lab and perhaps have an office? Or is there more to it than that? I was asked to write a letter of recommendation for a professor I had to turn him from an assistant professor into a full-fledged (and perhaps tenure track?) professor. He's a good teacher so I was happy to do it, but I found it a little odd that the professor in charge of this whole process said, "If you don't feel you can write a letter that presents [this guy] in a positive light, it's OK -- let me know and we'll find someone else." Hmmm....! > Some day I will, when I throttle back design work and money (hopefully) > isn't a big issue. It doesn't have to be any ritzy school as long as the > audience is motivated and the school isn't a huge driving distance away. These days "distance learning" is becoming quite popular. You could probably host your own classes on more advanced/specialized topics (where they might not be enough people interested to get an actual physical class together in a smaller town), set it up so that everyone gets audio & video and remote students can send back audio (for questions/discussion), charge tuition to cover the conference server feels, your costs and compensation, etc. and be quite successful. Doug Smith (http://www.emcesd.com/) appears to have done pretty well with his approach of giving away a *significant* amount of useful information for free and then having a subscription service for those who want even more. ---Joel >> There shouldn't be any tenure in the first place. There is a reason why the >> tenure concept does not exist in industry. Just my humble opinion. [quoted text clipped - 3 lines] > generally still allowed to come and play in the lab and perhaps have an > office? Or is there more to it than that? Plus probably a nice retirement benefit. > I was asked to write a letter of recommendation for a professor I had to turn > him from an assistant professor into a full-fledged (and perhaps tenure > track?) professor. He's a good teacher so I was happy to do it, but I found > it a little odd that the professor in charge of this whole process said, "If > you don't feel you can write a letter that presents [this guy] in a positive > light, it's OK -- let me know and we'll find someone else." Hmmm....! That is strange. Normally they should have known this guy inside out before even offering tenure if that's what his new position entails. >> Some day I will, when I throttle back design work and money (hopefully) >> isn't a big issue. It doesn't have to be any ritzy school as long as the [quoted text clipped - 7 lines] > cover the conference server feels, your costs and compensation, etc. and be > quite successful. True, but I am a believer in face to face sessions when it comes to explaining EE matters. You can't beat the hands-on training in front of a big scope or analyzer. "Sir, I can't get that dang thang to trigger!" > Doug Smith (http://www.emcesd.com/) appears to have done pretty well with his > approach of giving away a *significant* amount of useful information for free > and then having a subscription service for those who want even more. Yes, his site is indeed excellent. I am surprised IEEE lets him publish his papers. When I wrote papers for IEEE transactions there was a pretty clear statement that you pretty much surrender copyright to them. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > That is strange. Normally they should have known this guy inside out before > even offering tenure if that's what his new position entails. I believe they did know him inside and out, were happy with his performance, and that's why it happened: They had already decided they were going to offer him the promotion, but some standard procedure required getting a student evaluation as well... so they had to find someone who was willing to write up a positive one. I just think it's strange that they bother getting a student evaluation when their minds are already made up... since it then puts them in the rather awkward position of having to say, "Please write us a good evaluation, or if you don't feel you can, that's OK, we'll find someone else..." Weird. Perhaps they'd do better to ask a handful of students to write up objective evaluations without the pressure of "...but, um, it has to be positive?" -- and then culling any that were negative? :-) I suppose they're stuck in a way... being tied to the government (they're a land-grant university) means they have to follow lots of procedures that regular businesses don't. Regarding the nice retirement packages... my understanding was that state workers ended up with rather cushy retirement packages in exchange for having to accept noticeably below-average salaries (relative to private industry) during their working years. In Oreogn we have the PERS (Public Employee Retirement System) which used to work this way, but the "cushy" benefits were signifcantly reduced via the ballot box when some interested parties pointed out how much better PERS was than what those folks in private industry get. Hence you now have a system where public employee pay still isn't competitive with private industry and now the retirement isn't either! This was a common topic of complaint by the professors (that you'd get to know well enough) when I was in grad school; a significant number left for private industry during that time, and I certainly coudn't blame them. That being said, I don't know enough to evaluate whether or not public jobs are still attractive when you look at the total package -- some people would argue they are and that PERS benefit reductions were just "corrections" to a system that had become too "generous" in its compensation. ---Joel >> That is strange. Normally they should have known this guy inside out before >> even offering tenure if that's what his new position entails. [quoted text clipped - 32 lines] > argue they are and that PERS benefit reductions were just "corrections" to a > system that had become too "generous" in its compensation. All I know from here (CA) is that their benefits are mind-boggling. Paid sick leave, fat disability payments where lots of people tried and succeeded to be declared "disabled", cradle-to-grave medical with hardly any co-pay. The latter alone will saddle our communities with previously unheard of debt. Oh, and then lots of jobs have the retirement benefit tied to the last work year. So, folks have themselves transferred into high-cost areas such as the Bay Area for 13 months or so, then move back. That ratchets their monthly checks up substantially, until their dying day. That ain't right. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > All I know from here (CA) is that their benefits are mind-boggling... Well, it's entirely reasonable to have retirement benefits for public employees be comparable to what private companies offer... I just hope that public employee salaries will then become comparable as well (which implies a pay raise), since otherwise I don't see how the gov't. expects they'll get comparable quality out of their workers. One problem with the government seems to be that they don't expect their employees to be agile over time. See this article: http://www.gcn.com/print/24_30/37174-1.html -- Someone the government ends up with a bunch of 70 year old programmers and therefore has to hire IBM to build them the modernized e-filing systems? Surely there must be some new hires in the past, say, 40 years who could have been working on this and hence, on average, would only be middle-aged today!? > Oh, and then lots of jobs have the retirement benefit tied to the last work > year. I expect that was implemented to help people who were *forced* to move? It seems like it needs reworking to differentiate between cases where the government wants to move you vs. you just voluntarily wanting to do so. ---Joel >> All I know from here (CA) is that their benefits are mind-boggling... > [quoted text clipped - 3 lines] > pay raise), since otherwise I don't see how the gov't. expects they'll get > comparable quality out of their workers. Private companies generally offer zilch in retirement benefits. Those days are long gone. > One problem with the government seems to be that they don't expect their > employees to be agile over time. See this article: [quoted text clipped - 3 lines] > the past, say, 40 years who could have been working on this and hence, on > average, would only be middle-aged today!? A 70 year old programmer can be better than a 40 year old. At least that's my impression when I see all the "modern" bloatware ;-) >> Oh, and then lots of jobs have the retirement benefit tied to the last work >> year. [quoted text clipped - 3 lines] > It seems like it needs reworking to differentiate between cases where the > government wants to move you vs. you just voluntarily wanting to do so. Or you just have to have the right connections to make that happen ... Anyhow, why should retirement checks be based on the last year of service? IMHO that's wrong. For everyone else it sure doesn't work that way. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > >> All I know from here (CA) is that their benefits are mind-boggling... > > [quoted text clipped - 6 lines] > Private companies generally offer zilch in retirement benefits. Those > days are long gone. I don't know about "gone". The age of the "defined benefit" is pretty much gone in private industry but several still have "defined contribution" plans. Now, 401Ks make up for a lot of what's been lost and are portable. > > One problem with the government seems to be that they don't expect their > > employees to be agile over time. See this article: [quoted text clipped - 6 lines] > A 70 year old programmer can be better than a 40 year old. At least > that's my impression when I see all the "modern" bloatware ;-) Maybe. There are better things to do at 70, though. ;-) > >> Oh, and then lots of jobs have the retirement benefit tied to the last work > >> year. [quoted text clipped - 8 lines] > Anyhow, why should retirement checks be based on the last year of > service? IMHO that's wrong. For everyone else it sure doesn't work that way. The last years' is indicative of the final salary. Most "defined benefit" plans do take the last year, or last couple of years into account. What most private pensions *don't* do, that public plans do is include overtime in the formula. It's not hard to double one's income for a couple of years. There is no way the tax payer should pay that forever. SignatureKeith >>>> All I know from here (CA) is that their benefits are mind-boggling... >>> Well, it's entirely reasonable to have retirement benefits for public [quoted text clipped - 10 lines] > contribution" plans. Now, 401Ks make up for a lot of what's been > lost and are portable. Sure, but 401(k) is generally funded by the employee. Occasionally the company throws in a little extra but that is mostly a mere drop in the bucket in contrast to the lavish pension plans that cover many state workers. >>> One problem with the government seems to be that they don't expect their >>> employees to be agile over time. See this article: [quoted text clipped - 8 lines] > > Maybe. There are better things to do at 70, though. ;-) Yes, definitely. OTOH completely quitting a career has brought many fine engineers into the grave within less than a year. My father who worked as a data processing engineer continued as a consultant and gradually tapered it off. He said that there was a rash of unexpected deaths of otherwise quite healthy colleagues right after retirement, and it was among the group of engineers who shut their careers down more or less overnight after the first retirement check arrived. >>>> Oh, and then lots of jobs have the retirement benefit tied to the last work >>>> year. [quoted text clipped - 14 lines] > one's income for a couple of years. There is no way the tax payer > should pay that forever. But it's happening. And we are all paying for that. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > >>>> All I know from here (CA) is that their benefits are mind-boggling... > >>> Well, it's entirely reasonable to have retirement benefits for public [quoted text clipped - 15 lines] > bucket in contrast to the lavish pension plans that cover many state > workers. It's quite normal for a company to add significantly to the 401K, sometimes with strings attached, sometimes without. My PPOE had a fairly decent 401K (in addition to pension plans for everyone joining before '06, or so). They matched 1:1 up to 6% of salary (plus bonusus) and had no management fees for the normal funds. I understand it's gotten better since they've dropped the pension plans for the newbs. > >>> One problem with the government seems to be that they don't expect their > >>> employees to be agile over time. See this article: [quoted text clipped - 16 lines] > among the group of engineers who shut their careers down more or less > overnight after the first retirement check arrived. I got quite bored, once I wasn't allowed to make messes at home anymore. Good thing that only lasted a week or two. ;-) > >>>> Oh, and then lots of jobs have the retirement benefit tied to the last work > >>>> year. [quoted text clipped - 16 lines] > > But it's happening. And we are all paying for that. Precisely. It's not going to get better. The government requires others to have fully funded retirement plans, but would have none of it for themselves. SignatureKeith >> >>>> All I know from here (CA) is that their benefits are mind-boggling... >> >>> Well, it's entirely reasonable to have retirement benefits for public [quoted text clipped - 72 lines] >others to have fully funded retirement plans, but would have none of >it for themselves. Actually CalPERS is one exception to the slightly over broad brush. Of course over 2E11 dollars is not a toy. >> >> All I know from here (CA) is that their benefits are mind-boggling... >> > [quoted text clipped - 44 lines] >one's income for a couple of years. There is no way the tax payer >should pay that forever. So you say. While there are classes where that is easily done it is usually in the mid range hourly and low range salaried that it is reasonably possible. But how may 50+ year olds do you know that can and will work significant overtime? >>>>> All I know from here (CA) is that their benefits are mind-boggling... >>>> Well, it's entirely reasonable to have retirement benefits for public [quoted text clipped - 44 lines] > and will work significant overtime? > Plenty around here. Usually in law enforcement. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > >> >> All I know from here (CA) is that their benefits are mind-boggling... > >> > [quoted text clipped - 49 lines] > reasonably possible. But how may 50+ year olds do you know that can > and will work significant overtime? Overtime should never be needed in a well run company. That said, I've been averaging 60hr weeks (some 70+ and a few weeks with holidays, less) since August and have at least a few more months of work left on the pile, if I want it. There is no reason a 50s can't work overtime but there is also no reason to need, want, or expect it. BTW, I certainly wouldn't be working the overtime were I salaried. SignatureKeith >>>>>> All I know from here (CA) is that their benefits are mind-boggling... >>>>> Well, it's entirely reasonable to have retirement benefits for public [quoted text clipped - 50 lines] > it. BTW, I certainly wouldn't be working the overtime were I > salaried. So what do you do at the end of this gig? Maybe buy Adnan Kashoggi's yacht ;-) SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > >>>>>> All I know from here (CA) is that their benefits are mind-boggling... > >>>>> Well, it's entirely reasonable to have retirement benefits for public [quoted text clipped - 53 lines] > So what do you do at the end of this gig? Maybe buy Adnan Kashoggi's > yacht ;-) Every hour I work now is at least two I don't have to later. ;-) As they say, "you gotta make hay while the sun is shining". SignatureKeith > Every hour I work now is at least two I don't have to later. ;-) > As they say, "you gotta make hay while the sun is shining". And Moonshine, when it isn't! Signaturehttp://improve-usenet.org/index.html Use any search engine other than Google till they stop polluting USENET with porn and junk commercial SPAM If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm Hi Joerg, > Private companies generally offer zilch in retirement benefits. Those days > are long gone. Actually I think a very significant fraction of companies (at least those hiring EEs) offer some sort of contribution to 401k plans, sometimes profit sharing, sometimes stock options, etc... but I concur that the old days of "company pensions" is pretty much gone. > A 70 year old programmer can be better than a 40 year old. Absolutely, but if you're an employer it's definitely a legitimate consideration that starting a bunch of 70-year-olds on a, say, decade-long "modernization" project is rather riskier than if you toss a few 50- or 30-year-olds into the mix as well. :-) > Anyhow, why should retirement checks be based on the last year of service? > IMHO that's wrong. I agree that one year seems too short, but trying to figure out how many years should be taken into consideration (which is effectively what happens in private companies if the company is contributing to your 401k) is not going to be easy either. ---Joel > Hi Joerg, > [quoted text clipped - 5 lines] > sharing, sometimes stock options, etc... but I concur that the old days of > "company pensions" is pretty much gone. Mostly it's a mere pittance. And that's ok, I am a strong believer that everyone should pull their own weight. Except disabled people, of course. >> A 70 year old programmer can be better than a 40 year old. > > Absolutely, but if you're an employer it's definitely a legitimate > consideration that starting a bunch of 70-year-olds on a, say, decade-long > "modernization" project is rather riskier than if you toss a few 50- or > 30-year-olds into the mix as well. :-) True. However, we should embrace the Japanese concept of letting older folks teach the young ones, not lay them off. >> Anyhow, why should retirement checks be based on the last year of service? >> IMHO that's wrong. [quoted text clipped - 3 lines] > private companies if the company is contributing to your 401k) is not going to > be easy either. Just make it the same as with 401(k), IRA, old style pension funds, social security etc. What counts is what you pay in over your whole career. We can read such stories almost daily, just an example from this morning: http://www.sacbee.com/111/story/876845.html Guess who gets to pay the tab for the agency's legal defense? SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > Mostly it's a mere pittance. And that's ok, I am a strong believer that > everyone should pull their own weight. I guess it depends on the employer... Do you see anything bad about the old system of pensions (from private companies, ignore the government for the moment)? I see them more as "different" than particularly better or worse. These days you're personally responsible for more of your retirement planning, which has the upside that you can probably do a better job than some company-wide pension programs used to do, but the downside is that those who plan poorly (or not at all) end up needing that much more government assistance once they're retired. > True. However, we should embrace the Japanese concept of letting older folks > teach the young ones, not lay them off. Yes, agreed 100%. > Just make it the same as with 401(k), IRA, old style pension funds, social > security etc. What counts is what you pay in over your whole career. The end result there is that if your employer requires you to move to, e.g., California for the last few years of employment you'll pretty much be forced to then immediately move when you hit retirement. I suppose that isn't particularly awful, since that fact would have been clear when the employer said, "move!" > Guess who gets to pay the tab for the agency's legal defense? Sheesh... screw the taxpyers with retiremend funding and then screw'em again when someone tries to blow the whistle. Nice... ---Joel >> Mostly it's a mere pittance. And that's ok, I am a strong believer that >> everyone should pull their own weight. [quoted text clipped - 27 lines] >Sheesh... screw the taxpyers with retiremend funding and then screw'em again >when someone tries to blow the whistle. Nice... Finally, someone else caught on. >---Joel >> Hi Joerg, >> [quoted text clipped - 8 lines] >Mostly it's a mere pittance. And that's ok, I am a strong believer that >everyone should pull their own weight. Except disabled people, of course. My company contributes 15% of employee salaries (including bonuses) to their 401K. It's tax deductable to the company, not taxable to the employees, and makes everybody happy. That's what really matters, after all. But it's not a pension, in that the company has no obligations at all. John >>> Hi Joerg, >>> [quoted text clipped - 12 lines] > employees, and makes everybody happy. That's what really matters, > after all. Yes, but all along I've had the impression that your company does a lot more for emplyee motivation than most others. 15% is huge. > But it's not a pension, in that the company has no obligations at all. And it shouldn't be. Employees must understand that investing it is their responsibility, not yours. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. >> Hi Joerg, >> [quoted text clipped - 8 lines] >Mostly it's a mere pittance. And that's ok, I am a strong believer that >everyone should pull their own weight. Except disabled people, of course. Actually i have found an amazing amount of them that can do just that. I expect you have heard of Steven Hawking? >>> A 70 year old programmer can be better than a 40 year old. >> >> Absolutely, but if you're an employer it's definitely a legitimate >> consideration that starting a bunch of 70-year-olds on a, say, decade-long >> "modernization" project is rather riskier than if you toss a few 50- or >> 30-year-olds into the mix as well. :-) Correct. >True. However, we should embrace the Japanese concept of letting older >folks teach the young ones, not lay them off. There is a trade off there. You need to limit that to the most flexible and brightest old personnel. >>> Anyhow, why should retirement checks be based on the last year of service? >>> IMHO that's wrong. [quoted text clipped - 6 lines] >Just make it the same as with 401(k), IRA, old style pension funds, >social security etc. What counts is what you pay in over your whole career. Heavily weighted by the early amounts because of compound interest. Check it out. Moreover, no matter what the contributions were there should come a point where the interest on the early contributions outweigh the current contributions. Do the arithmetic. A spreadsheet program makes this relatively painless. >We can read such stories almost daily, just an example from this morning: >http://www.sacbee.com/111/story/876845.html > >Guess who gets to pay the tab for the agency's legal defense? >>> Hi Joerg, >>> [quoted text clipped - 9 lines] > Actually i have found an amazing amount of them that can do just that. > I expect you have heard of Steven Hawking? Yes, a remarkable guy. I didn't mean folks who develop Lou Gehrig's although they will also need support once it has progresed to a point. I mean people like the guy with Down syndrome we sometimes visit. He's on disability and that is really the only way for him to live. >>>> A 70 year old programmer can be better than a 40 year old. >>> Absolutely, but if you're an employer it's definitely a legitimate [quoted text clipped - 7 lines] > There is a trade off there. You need to limit that to the most > flexible and brightest old personnel. That would be no problem. >>>> Anyhow, why should retirement checks be based on the last year of service? >>>> IMHO that's wrong. [quoted text clipped - 10 lines] > outweigh the current contributions. Do the arithmetic. A spreadsheet > program makes this relatively painless. I don't think we'll see the interest rates of yesteryear anytime soon. But the point is there should not be preferential treatment of public service employees on the shoulders of the taxpayer. >> We can read such stories almost daily, just an example from this morning: >> http://www.sacbee.com/111/story/876845.html >> >> Guess who gets to pay the tab for the agency's legal defense? SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. >>>> Hi Joerg, >>>> [quoted text clipped - 47 lines] >But the point is there should not be preferential treatment of public >service employees on the shoulders of the taxpayer. Preferential? I think not. Civil service employees generally get what was normal in industry 10 years ago. They usually trade job security for about a sixth less pay. It is the near invulnerable job security that is the problem. >>> We can read such stories almost daily, just an example from this morning: >>> http://www.sacbee.com/111/story/876845.html >>> >>> Guess who gets to pay the tab for the agency's legal defense? >>>>> Hi Joerg, >>>>> [quoted text clipped - 52 lines] > security for about a sixth less pay. It is the near invulnerable job > security that is the problem. But: John Doe does not get what was normal in industry 10 years ago. He just gets ever increasing property tax and other bills. Followed by eternal lamentations that those taxes aren't enough. The litmus test is this: When an agency receives boatloads of applications like it supposedly happens for the prison guard jobs then something is seriously out of balance. And yes, I agree with you that tenure track should not exist. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. >>> That is strange. Normally they should have known this guy inside out before >>> even offering tenure if that's what his new position entails. [quoted text clipped - 34 lines] > >All I know from here (CA) is that their benefits are mind-boggling. OK lets get to that. >Paid sick leave, Not particularly uncommon until you get to low end hourly. Standard for engineers since WWII. > fat disability payments where lots of people tried and >succeeded to be declared "disabled", Yes there has been abuses. >cradle-to-grave medical with hardly any co-pay. When i worked for private as an engineer it was $5 for office visit, $20 for lab, $5 per prescription. Today with State of CA it is $10 or more for office visit, $0 for lab, $5 to $25 per prescription. It increases in retirement. Then Medicare is supposed to kick in and relieve much of the State burden. If you are 65 or older and don't like what you have try Medicare and see how well you like that. >The latter alone will saddle our communities with previously >unheard of debt. [quoted text clipped - 3 lines] >back. That ratchets their monthly checks up substantially, until their >dying day. That ain't right. It has been changed to the highest paid three years average in the last ten. And it now takes ten years to become "vested", instead of five. Now, you have been reading my stuff for some years now, do you think i am a doofus parading as an engineer? When i was hired some 15 years ago a PE could only expect about $5000 a month in State service. What was your monthly average then. What was it 5 years ago? What is it today. CA State pay rates for engineers and almost all others is a matter of public record. Try looking them up for yourself. You would do well to start with www.spb.ca.gov. Better still, compare them to County and City rates for the last 20 years. And finally note that for most cases the State does not give you a better paycheck based on where the job is, let alone where you live. 80 percent to 90 percent of half to two thirds of what a private engineer can make ain't all that much. You may get a lower top percentage, but it is / was based on a much better salary. >>>> That is strange. Normally they should have known this guy inside out before >>>> even offering tenure if that's what his new position entails. [quoted text clipped - 38 lines] > Not particularly uncommon until you get to low end hourly. Standard > for engineers since WWII. Most people I know don't. >> fat disability payments where lots of people tried and >> succeeded to be declared "disabled", > Yes there has been abuses. Big time. I've seen lots of it. People who collected fat checks because of back injuries and then personally erecting retaining walls and stuff. IMHO there is an utter lack of enforcement. Hey, didn't even Spike Helmick try to collect a fat pension "upgrade" claiming he fell off his armchair? >> cradle-to-grave medical with hardly any co-pay. > When i worked for private as an engineer it was $5 for office visit, [quoted text clipped - 3 lines] > relieve much of the State burden. If you are 65 or older and don't > like what you have try Medicare and see how well you like that. I must pay $65 for an office visit. Plus the first $2700 (per person!) per year out of pocket, else the premiums become unbearable. A lot of engineers I know how no health insurance at all because they can't afford it any longer. >> The latter alone will saddle our communities with previously >> unheard of debt. [quoted text clipped - 6 lines] > last ten. And it now takes ten years to become "vested", instead of > five. That's good but still not fair compared to people in non-gvt jobs. > Now, you have been reading my stuff for some years now, do you think i > am a doofus parading as an engineer? When i was hired some 15 years [quoted text clipped - 11 lines] > percentage, but it is / was based on a much better salary. > Half? $5k/mo is about what engineers in industry made 15 years ago. But the real perks are in other jobs where the legislature has caved in to the unions. Prison guards etc. A while ago the news reported the staggering number of applications sent in. It may not be a fun job but it sure must have become a plum job. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > But the real perks are in other jobs where the legislature has caved in to > the unions. Prison guards etc. A while ago the news reported the staggering > number of applications sent in. It may not be a fun job but it sure must > have become a plum job. I know of a friend of a friend who's a prison guard, and besides the money, one nice option they have here in Oregon is that they can completely swap hours with their co-workers. This guy will take a couple months off during the summer and then work a bunch of 60 hour weeks the rest of the year for someone else who's then taking his few months off. Definitely some advantages to having a job where you're largely interchangeable with any of your co-workers and are being paid by the hour! Of course, prison guard jobs are kind of like mining jobs... usually it's good pay and no problems, but when something does go wrong you're rather likely to end up dead... >>>>> That is strange. Normally they should have known this guy inside out before >>>>> even offering tenure if that's what his new position entails. [quoted text clipped - 88 lines] >> for most cases the State does not give you a better paycheck based on >> where the job is, let alone where you live. Current pay rates are here: http://www.dpa.ca.gov/publications/pay-scales/index.htm Please note some of the wild variation in engineer classifications. For this group we should look for electrical or electronic engineers. Senior engineer supervises working engineers, supervising engineers are the bosses of seniors, and they in turn report to principle engineers. I have not bothered to find historical pay rates yet. All of my peer group has made more in private than in public positions. If you are not doing as well, that is not my problem. >> 80 percent to 90 percent of half to two thirds of what a private >> engineer can make ain't all that much. You may get a lower top [quoted text clipped - 7 lines] >staggering number of applications sent in. It may not be a fun job but >it sure must have become a plum job. >>>>>> That is strange. Normally they should have known this guy inside out before >>>>>> even offering tenure if that's what his new position entails. [quoted text clipped - 102 lines] > group has made more in private than in public positions. If you are > not doing as well, that is not my problem. Research specialists making >10k/mo? That is a rather decent salary. Most researchers in industry do not make that much. Also, you have to consider that you guys have what almost amounts to tenure. When the budget is tight the taxpayer is expected to jump in. When the budget is tight in industry layoffs follow in due course. Right now EE is on a roll but remember 2001-2004? How many folks with masters degrees did low-wage jobs at hardware stores selling weed eaters and circular saws? I've met some. That (usually) does not happen to people in public service positions. [...] SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. > Research specialists making >10k/mo? That is a rather decent salary. > Most researchers in industry do not make that much. [quoted text clipped - 6 lines] > circular saws? I've met some. That (usually) does not happen to people > in public service positions. Marion County, Florida recently laid off about half of it's building inspectors and support staff. The trucks they drove were auctioned off a few days ago, as well. That money will go back into the county's general fund, as well as the unused salaries. Signaturehttp://improve-usenet.org/index.html Use any search engine other than Google till they stop polluting USENET with porn and junk commercial SPAM If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm > > Research specialists making >10k/mo? That is a rather decent salary. > > Most researchers in industry do not make that much. [quoted text clipped - 11 lines] > a few days ago, as well. That money will go back into the county's > general fund, as well as the unused salaries. One of the local sheriffs just handed out pink slips to about half his deputies and staff. He's looking for more tenants for his hotel, to pay for those remaining. Maybe he should ask Joe Arpaio for some help. SignatureKeith > One of the local sheriffs just handed out pink slips to about half > his deputies and staff. He's looking for more tenants for his > hotel, to pay for those remaining. Maybe he should ask Joe Arpaio > for some help. Some cities are claiming that they are going to have to lay off the police, close the fire departments, and stop ambulance services after not getting the huge increases they demanded. It is going to be a slaughterhouse at election time. Signaturehttp://improve-usenet.org/index.html Use any search engine other than Google till they stop polluting USENET with porn and junk commercial SPAM If you have broadband, your ISP may have a NNTP news server included in your account: http://www.usenettools.net/ISP.htm >> Not anymore. Part of my daily bread is earned salvaging designs where >> someone thought "Oh, it's just slow stuff". But it ain't grampa's old SN7400 >> anymore, today's logic chips are fast. > >OK, ok, good point. Doesn't someone now have a logic family that's purposely >been slowed down due to this "problem?" [snippage] You can control edge rates (drive current) on FPGAs, at least the Xilinx families we use. Amazing how simple you can make a DDR2 memory interface to a FPGA with a little thought. We get by with no terminations with beautiful looking signals. That saves a lot of power and board area. --- Mark > > "Joerg" <notthisjoerg...@removethispacbell.net> wrote in message > [quoted text clipped - 122 lines] > - what tools do that? Also curious about any timing issues that have > been caught after the pin-swap. In Altium Designer I use the incredibly useful "subnet jumper" feature for BGA's. The procedure goes something like this: 1) Fan out all the required FPGA pins first (automatically or manually) to just outside the chip boundry. (leave several diagonal entry paths for core and other power flood fills to get in) 2) Fully route all non-pin-swappable pins and other critical lines. 3) Ensure any other parts placements are near any required FPGA pins or block features you think you might need. 4) Route every track just short of the fanout tracks 5) Hit the "add subnet jumper" feature and it finishes the tracks and does all the pin swaps for you and updates the schematic. Probably needs a picture or two to explain it best though... The great part about subnet jumpers is if there are timing or other problems you can just remove the subnet jumpers and add/edit tracks and pins as needed and then replace the subnet jumpers. Only takes a minute or two. Dave. > 5) Hit the "add subnet jumper" feature and it finishes the tracks and > does all the pin swaps for you and updates the schematic. Sounds like a really nice feature, David -- thanks for the tip. >> > "Joerg" <notthisjoerg...@removethispacbell.net> wrote in message >> [quoted text clipped - 144 lines] > >Dave. That does sound specific to one particular tool (vendors's software). > That does sound specific to one particular tool (vendors's software). Yeah, after Dave posted that I checked and unfortunately Pulsonix can't do it... although it's "close enough" that I imagine adding it as a feature wouldn't be particularly difficult. I think it's a good idea -- hopefully it will show up in more tools over time. On Apr 25, 9:31 am, "Joel Koltner" <zapwireDASHgro...@yahoo.com> wrote: > > That does sound specific to one particular tool (vendors's software). > > Yeah, after Dave posted that I checked and unfortunately Pulsonix can't do > it... although it's "close enough" that I imagine adding it as a feature > wouldn't be particularly difficult. I think it's a good idea -- hopefully it > will show up in more tools over time. There's a new tool on the market for this - Taray's 7 Circuits http://www.tarayinc.com/ You do minimal floorplanning right in the tool, and it optimizes the I/ O assignment for the specific electrical characteristics of the device, and the arrangements of the other major devices the FPGA is connected to. Works with both Cadence and Mentor schematics. The nice part is that the EE doesn't have to actually do any PCB layout, but it makes the layout flow much better (fewer vias, layers, shorter connections, etc). -Brian > On Fri, 18 Apr 2008 00:09:02 -0700 (PDT), "David L. Jones" > [quoted text clipped - 150 lines] > > That does sound specific to one particular tool (vendors's software). Yes, it is specific to Altium Designer. It's their way of simplifying FPGA design and layout. Dave. >>>> Does anybody out there have a good methodology for determining your >>>> optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 96 lines] > >Steve Pretty much honest responses. Almost all of good value. Mark hinted and Joerg mentioned one of the foremost subjects, floorplanning. This will impact everything you do. From the original schematic drawing to the FPGA VHDL/Verilog coding and optimizing to PWB layout , documentation, and testing. Each of these activities requires floorplanning to get good results. To achieve the best PWD layout results make several different versions for your first few boards and route them all to completion. It will make huge improvements in your understanding. >>>>> Does anybody out there have a good methodology for determining your >>>>> optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 107 lines] > improvements in your understanding. > Right. The same goes for code, especially micro controllers. Without spending a lot of time on a floor plan chances are it won't fit in or it'll become a hodge-podge of code snippets somehow stitched together. Seen a lot of that :-( There seems to be a huge software company up north that has in part lost the art of good floorplanning ... SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. >>>>>> Does anybody out there have a good methodology for determining your >>>>>> optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 115 lines] >There seems to be a huge software company up north that has in part lost >the art of good floorplanning ... Actually it never had it. >>>>>>> Does anybody out there have a good methodology for determining your >>>>>>> optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 115 lines] > Actually it never had it. > :-) Although I must say that the folks who designed MS-Works did a fine job. Even the Windows versions of it never crashed on me. That is quite unusual for Windows programs. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. Dave We are slightly unusual in that we started as FPGA design house and now probably better known for our boards even though we do an awful lot of internal FPGA design still. A lot of board layout is just common sense. Having a plan of how it all fits together - not just placement but routing runs between chips usually pays great dividends. Having someone who understands both the FPGA and the pcb layout is usually a great advantage as it allows tradeoffs to be made easily and generally ends up with with a better board. Swaping I/Os as you layout will give a much better results. That all said we are still learning on our pcb design skills even after producing development boards for nearly 5 years and I can still say generally that every new board we do is technically better than the previous one we did. Your first board will probably take a long time especially if it as in any way complex. Our first development board (Broaddown2 for the interested) that we released took about 800hrs of man effort. We would do that same board now in probably less than 1/3 of that time now. So in summary you have the difficult decision whether to invest time in learning the trade, making mistakes along the way, and possibly getting better boards versus the direct cost of using someone experienced and reducing the risks of a good enough to ship first layout. Very few people achieve boards that are good enough to ship as practical production boards as first revisions and if you do that you are doing well. Wire mods etc in production cost lots. I'm know of some designs done by customers themselves that have gone to 7 versions due to mistakes in layout. That's not cheap and really hits timescales. I'm proud to say my team have delivered over 50% of our development boards to production, to ship at 1st issue, but that is definately unusual in boards of that level of complexity. Board can be an enjoyable task but it's not for the impatient. John Adair Enterpoint Ltd. > Does anybody out there have a good methodology for determining your > optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 14 lines] > > Dave >Does anybody out there have a good methodology for determining your >optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? >The brute force method is fairly maddening. I'd be curious to hear if >anybody has any 'tricks of the trade' here. What's the brute force method? We preassign most fpga pins for clean, no-crossover routing to other chips. We discuss the general issues, especially placement, with our pcb layout guy and he actually decides which pins go where. Then he back-annotates the schematic and gives us a file we can use to create the fpga pin constraints file. Sometimes bank issues complicate the process, but it works pretty well. >Also, just out of curiosity, how many of you do your own PCB layout, >versus farming it out? It would certainly save us a lot of money to >buy the tools and do it ourselves, but it seems like laying out a >board out well requires quite a bit of experience, especially a 6-8 >layer board with high pin count FPGA's. We'd never farm it out. We do critical mixed-signal stuff, and need to be near our layout guy constantly. He puts up a version on our server daily at least, and we keep an eye on progress. And we have a lot of mini-meetings to change the rules as needed. Besides, we have evolved some styles (and libraries!) that we couldn't very well transfer to a service bureau. PCB layout is too important to farm out. >We're just setting up a hardware shop here, and although I've been >doing FPGA and board schematics design for a while, it's always been >at a larger company with resources to farm the layout out, and we >never did anything high-speed to really worry about the board layout >too much. Thanks in advance for your opinions. For really critical stuff, sometimes I'll take over and route that part of the board myself. It's just too hard to communicate exactly what I want. John >> Does anybody out there have a good methodology for determining your >> optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? [quoted text clipped - 20 lines] > some styles (and libraries!) that we couldn't very well transfer to a > service bureau. PCB layout is too important to farm out. I always farm out the layout. At the most I do a mock layout of, say, a hotrod RF amp area and send it to the layouter. During layout Gerbers go back and forth all the time, sometimes in 15min intervals. Once my layouter had to be in Vermont during the job, no problem. Crunch time, he worked into the night, I had a laptop in the living room and whenever it beeped I'd go into the office, check the Gerbers and reply. Also really nice was a company overseas. I only had to check some critical areas during layout (which was done over there). They used a subversion system so a scattered team could cooperate without accidentally stepping on each others files. It was almost as if their server was here in the basement. >> We're just setting up a hardware shop here, and although I've been >> doing FPGA and board schematics design for a while, it's always been [quoted text clipped - 5 lines] > part of the board myself. It's just too hard to communicate exactly > what I want. Yes, for really hot stuff it's good to sit next to each other. In the past I'd driver over there and me, the layouter and his cat would do the tough parts of the layout together. Unfortunately his cat has passed away by now. SignatureRegards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM. >Does anybody out there have a good methodology for determining your >optimal FPGA pinouts, for making PCB layouts nice, pretty, and clean? >The brute force method is fairly maddening. I'd be curious to hear if >anybody has any 'tricks of the trade' here. I start thinking about how the PCB should be routed the minute I start to draw a schematic. I always draw components with their actual pin-outs. This helps to group pins together and it helps to troubleshoot the circuit when the prototype is on your bench (no need to lookup the pinouts because they are in your diagram). >Also, just out of curiosity, how many of you do your own PCB layout, >versus farming it out? It would certainly save us a lot of money to >buy the tools and do it ourselves, but it seems like laying out a Whether you should do PCB layout by yourself or hire someone to do it for you depends on if you have the time and talent to design a PCB. After all at high frequencies and / or large currents a PCB becomes a component of your circuit. SignatureProgrammeren in Almere? E-mail naar nico@nctdevpuntnl (punt=.) > I always draw components with their actual >pin-outs. What does that mean? SignatureThese are my opinions, not necessarily my employer's. I hate spam. >> I always draw components with their actual >> |
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