| --- Thu Dec 22 2011 | 00:00 | |
| azonenberg | Hi guys | 14:52 |
|---|---|---|
| azonenberg | Just built myself a new toy, http://i.imgur.com/TvI3s.jpg | 14:53 |
| azonenberg | experiments will be resuming shortly | 14:53 |
| soul-d | nice whats the cabin material made off | 14:54 |
| azonenberg | 1/8" PVC from Mcmaster-Carr, held together with L-brackets | 14:54 |
| azonenberg | 1/8" clear acrylic on the sash | 14:54 |
| azonenberg | 240cfm duct fan | 14:55 |
| azonenberg | whcih on the 1x2 foot opening gives 120 linear FPM, minus a bit for the cracks (joints arent caulked etc) and you get 80-100 | 14:55 |
| azonenberg | well within the safe range | 14:55 |
| azonenberg | i tested with IPA and acetone and it kept concentrations well below the odor threshold at all times | 14:55 |
| azonenberg | whcih, depending on who you ask, is 40-100 PPM for acetone and the safe exposure limit is 500-1000 depending on the regulators you ask | 14:56 |
| azonenberg | So i'm well within safe limits | 14:56 |
| azonenberg | IOW, the thing actually works | 14:56 |
| soul-d | nice had 500m3 somthing fan deliverd today :P probably overkill for that ;) | 14:57 |
| soul-d | i take those numbers are from woerking area | 14:57 |
| azonenberg | You actually dont want too high or you get fortices | 14:57 |
| soul-d | egg 8 hour work day ? | 14:57 |
| azonenberg | vortices* | 14:57 |
| azonenberg | which have a habit of leaking nasties out of the hood on the edges | 14:57 |
| azonenberg | hecne the 120fpm cap | 14:57 |
| azonenberg | and yes, the PEL i quoted was 8-hour time weighted | 14:58 |
| azonenberg | the MSDS listed three limits depending on agency but they were all 500-1000 PPM range for acetone | 14:58 |
| azonenberg | iirc all of the chemicals i work with except HF have the PEL significantly above the odor threshold | 14:58 |
| azonenberg | Meaning if you cant smell it, its safe | 14:58 |
| azonenberg | I wanted to test first with relatively safe substances like IPA | 14:59 |
| azonenberg | The next test will use something stronger like concentrated HCl | 15:00 |
| azonenberg | if i cant smell that at all from outside the hood i'm good :) | 15:00 |
| azonenberg | Odor threshold 0.25 to 10 PPM | 15:01 |
| azonenberg | personally i think the 10 is high, that stuff is pretty potent | 15:01 |
| soul-d | donno if i smelled that before id probably try to convert some amonia fertilizer to KNO3 since ive done that before | 15:02 |
| azonenberg | Concentrated hydrochloric acid is not something you are going to forget the smell of lol | 15:02 |
| soul-d | but then again chemistry is on hold still | 15:02 |
| soul-d | only have 30% and 10% | 15:02 |
| soul-d | but never opened the 30% yet | 15:03 |
| azonenberg | Mine is 32% i think | 15:03 |
| azonenberg | And do so with caution | 15:03 |
| azonenberg | It will most likely fume strongly | 15:03 |
| soul-d | it's 5 liters to :P havent touched it since i bought i lol donno even why :D | 15:03 |
| azonenberg | Five liters?? | 15:03 |
| azonenberg | Mine is a 1L bottle and i thought that was a lot | 15:03 |
| soul-d | stron concetrations only came in this package | 15:03 |
| azonenberg | i had trouble buying any less except in very high purity | 15:04 |
| soul-d | lol ? | 15:04 |
| azonenberg | not as in concentration | 15:04 |
| azonenberg | but like ACS reagent grade or trace metals basis | 15:04 |
| azonenberg | you can get in half-liter bottles | 15:04 |
| azonenberg | Technical grade the smallest i could get was 1L | 15:04 |
| soul-d | i had trouble finding it :) | 15:04 |
| azonenberg | where are you located again? | 15:04 |
| soul-d | oh still is wall cleaning grade | 15:04 |
| soul-d | netherlands | 15:04 |
| azonenberg | Well it's technical, but pretty high grade | 15:04 |
| azonenberg | as far as technical goes | 15:04 |
| azonenberg | I intend to buy some ACS grade when this runs out | 15:05 |
| azonenberg | but it's lasting me forever | 15:05 |
| azonenberg | just doing PCB etching etc with it | 15:05 |
| soul-d | still use ferric chloride for that | 15:05 |
| azonenberg | i use one part conc HCl to 6 parts 3% H2O2 | 15:05 |
| azonenberg | gently heated | 15:05 |
| azonenberg | it's stronger and also transparent | 15:06 |
| azonenberg | so you can watch the board etch | 15:06 |
| soul-d | probably be easyer to follow along true but i assumed that stuff was bit more nasty then this brown stuff | 15:07 |
| azonenberg | You do need better ventilation | 15:08 |
| azonenberg | But if you have it, the etch quality is superior | 15:08 |
| azonenberg | it also doesnt get rust stains on your glassware | 15:08 |
| azonenberg | cleans off nicely, all of the waste products are water soluble | 15:08 |
| soul-d | also have the sodium perchlorate stuff for etching somewhere | 15:08 |
| azonenberg | persulfate you mean? | 15:08 |
| azonenberg | perchlorate would probably blow up, not etch :p | 15:08 |
| soul-d | yes that srry :) | 15:08 |
| azonenberg | And when i'm done etching i just store the CuxClx contaminated waste in a jar until the next scheduled hazmat pickup | 15:09 |
| azonenberg | the county has one or two a year | 15:09 |
| soul-d | we do have a disposal thingy for chemicals | 15:09 |
| azonenberg | Yeah, I'm trying to run my lab as by-the-book as I can | 15:10 |
| azonenberg | even if the volumes involved probably arent large enough to matter | 15:10 |
| azonenberg | rather not take chances | 15:10 |
| azonenberg | And its a good habit to get into | 15:10 |
| azonenberg | for if i end up working in a commercial lab or handling larger volumes of stuff | 15:11 |
| soul-d | yeah thats why i stopped until reasonable buget/safe enviroment since im pretty clueless | 15:11 |
| soul-d | problem is hard to do self study | 15:11 |
| azonenberg | I figured an open window was probably good enough for what i was doing, not handling anything too nasty | 15:11 |
| azonenberg | But better engineering controls never hurt | 15:11 |
| azonenberg | So i decided to build the hood | 15:11 |
| azonenberg | Next step is going to be to use the aluminum stock i just ordered to machine a little jig | 15:12 |
| azonenberg | to hold my wafer over the evaporator basket so i can do nickel deposition | 15:12 |
| azonenberg | it sublimes so i cant use the tool's normal under-basket moun | 15:12 |
| azonenberg | which expects a material that melts before evaporating | 15:12 |
| azonenberg | At that point i'll be good to go for through-wafer etch testing | 15:13 |
| azonenberg | In parallel i have some ideas for improving lithography resolution | 15:13 |
| azonenberg | theoretically down to 330nm | 15:13 |
| azonenberg | but realistically i think 500-750 will be a limit with my optics | 15:13 |
| soul-d | you where at 22um now ? | 15:14 |
| azonenberg | It was nominally the 20um node but i think the exact half-pitch was 21 and change | 15:14 |
| azonenberg | generally overetch meant features were a little smaller than that and spaces a little larger | 15:14 |
| azonenberg | This is doing 10x reduction of a 200um mask | 15:14 |
| azonenberg | I'm going to buy 12.5um masks from a real mask shop | 15:15 |
| azonenberg | then try 4/10/40x reduction of them as well as contact printing | 15:15 |
| azonenberg | I dont know if i can project 12.5um features so i'm going to put some larger features on the mask too | 15:15 |
| azonenberg | probably 25 and 50 | 15:15 |
| azonenberg | i'm quite certain i can resolve 50 on the mask, times 10x reduction is 5um | 15:15 |
| azonenberg | so i can hit that as a minimum | 15:15 |
| azonenberg | but if i use the 40x objective (which has proven flaky in the past) i could potentially go 12.5um / 40x = ~330nm | 15:16 |
| azonenberg | again thats a theoretical number and i think 500-750 will be a practical limit | 15:16 |
| azonenberg | But submicron would be very nice | 15:16 |
| soul-d | true, spend bit to much on electronics so most projects came to grinding halt also since pc is getting old and buggy don't want to code to much on it | 15:20 |
| soul-d | mostly scavenging stuff that could be used | 15:20 |
| soul-d | was even looking back at amature telescope making for fun want to do some mirrors myself | 15:21 |
| azonenberg | Well, if you decide to build an evaporation or sputtering rig | 15:25 |
| azonenberg | let me know lol | 15:25 |
| azonenberg | we can collaborate on design | 15:25 |
| soul-d | long way to go still but shall see what 2012 will bring i do want to build more stuff | 15:28 |
| soul-d | both of those where with a vacume right only idea i had for evap is a basic high temp oven schematic 40 years old :P carbon rods and lots of power | 15:29 |
| soul-d | but i want allot like a ballanced buget book, get piece of community land to grow own food budget for rehabilitation need to gain lots of (healty ) weight | 15:41 |
| soul-d | anything that is left over is for learning purposes and projects :) | 15:45 |
| azonenberg | No, for evap there's a bit more involved | 15:59 |
| azonenberg | You want to use a tungsten filament coiled into a basket | 15:59 |
| azonenberg | You can buy them from Ted Pella among other vendors | 15:59 |
| azonenberg | Put pellets or wire of your material inside it | 15:59 |
| azonenberg | Then pump the chamber down to the 1E-6 torr range | 15:59 |
| azonenberg | and run current trough the filament | 16:00 |
| azonenberg | Generally speaking you'll want a couple of volts at pretty high current | 16:00 |
| azonenberg | tens to hundreds of amps | 16:00 |
| azonenberg | general control method is a variac off of wall power to control voltage, followed by a step-down transformer | 16:00 |
| soul-d | k yeah still have my eyes out on vacume sture thats probably the hardest part to get right | 16:09 |
| azonenberg | a large enough bell jar will cost $$, yes | 16:09 |
| azonenberg | then you'd need a roughing pump and a high-vac pump, probably a diffusion pump | 16:09 |
| azonenberg | you cant get deep enough to evaporate with only a mechanical pump | 16:09 |
| soul-d | 2 stage or somthing i thought you said ? | 16:09 |
| azonenberg | I have a 2-stage mechanical pupm but that only hits 4E-2 torr | 16:10 |
| azonenberg | you have to be able to hit the -6 range which means a diffusion or turbopump | 16:10 |
| azonenberg | the second are very expensive so for hobbyists it basically means you need a diffusion | 16:10 |
| azonenberg | Sputtering uses much less deep vacuum, you can hit that with a mechanical pump | 16:10 |
| azonenberg | But you need a source of inert gas (usually argon) and high voltage | 16:10 |
| azonenberg | So it poses its own set of problems | 16:10 |
| soul-d | high voltage is easy depending of current | 16:11 |
| soul-d | got 5 kv transformers :P | 16:11 |
| azonenberg | Depends on what you're sputtering, even 500 - 1kV might be enough | 16:11 |
| superkuh | http://superkuh.com/library/Physics/High%20Vacuum%20with%20Mechanical%20Pumps_%20A%20Summary%20of%20Work%20Done%20by%20Bruce%20Kendall%20and%20Others_%20BellJar_1999.pdf | 16:11 |
| azonenberg | But you need tens to low hundreds of watts | 16:11 |
| azonenberg | to power the plasma | 16:11 |
| azonenberg | This assumes DC sputtering, not RF | 16:11 |
| azonenberg | also, if you are doing a deposition of more than a small amount of material you need to cool the target | 16:12 |
| azonenberg | so it wont metl | 16:12 |
| azonenberg | melt* | 16:12 |
| azonenberg | small meaning <50nm probably | 16:12 |
| soul-d | my kv transformers are 400watts | 16:12 |
| soul-d | 3-4,5 kv | 16:13 |
| azonenberg | You might not want that much voltage depending on the material, i am more familiar with the basics of the process and not specific parameters so i could be wrong | 16:13 |
| soul-d | but thats for lighting L( | 16:13 |
| azonenberg | But the operating principle is similar to that of a neon sign | 16:13 |
| azonenberg | you strike a plasma through low-pressure inert gas | 16:13 |
| azonenberg | in fact, the plasma will glow very much like a neon sign | 16:14 |
| soul-d | tb | 16:14 |
| soul-d | there are plasma light's there day's | 16:14 |
| soul-d | but expensive to steal the transformer from | 16:14 |
| azonenberg | Lol | 16:14 |
| azonenberg | The only difference is that you tune the parameters for removing of material from the target (and depositing on your sample) and not for maximum brightness | 16:14 |
| soul-d | but will be along way before i start playing with high voltage though :) light bulb is bit easyers then above :P | 16:17 |
| azonenberg | Yeah, i dont trust my HV skills yet | 16:19 |
| soul-d | but this high rating tranformers start at 70watt | 16:19 |
| soul-d | for lights | 16:19 |
| azonenberg | i want to start slow and make sure i'm not going to electrocute myself :p | 16:19 |
| soul-d | hps and mh | 16:19 |
| soul-d | hpresure sodium and metalic halide or somthing | 16:20 |
| azonenberg | i see | 16:20 |
| soul-d | and 2 kinds electrincs ones i think done by som swithcing stuff or simple bloks of copper types ( like for TL but but bigger ) | 16:23 |
| soul-d | maybe look at what type of componets they use in electric types | 16:23 |
| azonenberg | I'm not too familiar with HV in general so i cant say | 16:25 |
| soul-d | me neither just hook up the light to grow peppers under it :P | 16:25 |
| soul-d | and glad i don't get shocked bu the system lol | 16:26 |
| soul-d | but still turn on all high voltage stuff on from a distance | 16:31 |
| azonenberg | Lol, yeah | 16:32 |
| azonenberg | Good practice | 16:32 |
| soul-d | yeah ever since i had to quickly try laserprinter 's stepper motor and plugged it in wrong way around chips do bang loud :) | 16:34 |
| soul-d | on the printers main board * | 16:34 |
| azonenberg | lol | 16:34 |
| soul-d | but i should make a picture of my shed :P | 16:40 |
| soul-d | you probably call it chemical hazard lol | 16:40 |
| azonenberg | lol | 16:40 |
| soul-d | now pots and pan's with kno3 and sugar to :) as smoke stuff to play around on new year a bit don't have a ball mill otherwise would made some candles | 16:43 |
| azonenberg | lol, ok thats pretty bad compared to my setup :p | 16:44 |
| soul-d | lol no it's worse | 16:44 |
| soul-d | maybe ill blur an image :P | 16:45 |
| soul-d | oh on picture it looks ever worse then in real :P | 16:47 |
| soul-d | but it will show you why im waiting on buget to fix the shed :P | 16:47 |
| soul-d | im so glad im not my neighbour -> http://i.imgur.com/QPs8F.jpg | 16:48 |
| soul-d | most of it is junk anyhow :P need to bring it away some day | 16:49 |
| soul-d | now ofcourse you where wondering what the oven is for :P | 16:50 |
| soul-d | i used that to heat kno3 and sugar :P | 16:50 |
| azonenberg | lol, ok | 16:50 |
| azonenberg | yeah, my place looks nowhere near that bad | 16:51 |
| azonenberg | i'm trying hard to make sure i'm as by-the-book as possible | 16:51 |
| soul-d | usaly before i do somthing i first need half a day to clean | 16:51 |
| azonenberg | lol wow | 16:52 |
| soul-d | if i knew winter was gonna be this hot | 16:53 |
| soul-d | i would have had it clean though | 16:53 |
| azonenberg | I'm actually in the process of tidying up the whole apt, roommates are gone and the semester is over | 16:53 |
| azonenberg | So now i can bring the place up to my usual standards | 16:54 |
| azonenberg | i'll post some pics including all of the new lab equipment once the cleaning is done | 16:54 |
| soul-d | yeah did home partly especialy since bought gazillion electrionics i need to get stuf sorted | 16:54 |
| soul-d | clean sorted work area does work better | 16:55 |
| soul-d | and less stress full | 16:55 |
| soul-d | but i need a reasonable buget | 16:56 |
| soul-d | not gonan fix that with few hunderd bucks | 16:56 |
| soul-d | since its single walled shed you cant realy store much | 17:02 |
| soul-d | metals rust | 17:02 |
| soul-d | read the vacume pdf for a bit so if i understand that system only reaches the wanted vacume if chilled (probably by liquid nitrogen ) ? | 17:41 |
| superkuh | Yes. You need to cool the zeolite (13x). | 17:42 |
| superkuh | The conductance between the zeolite and main chamber should be as large as possible as well. | 17:43 |
| soul-d | 13x stands for some industrie standard form of the zeolite stuff ? | 17:44 |
| superkuh | Yes. If I recall correctly it absorbs nitrogen and oxygen fairly well within the structure. I cannot recall the exact width of the cavities, some tens of nm. | 17:46 |
| superkuh | Er, wrong. | 17:47 |
| superkuh | Sorry. angstroms. | 17:47 |
| soul-d | i saw 8 passing by on google | 17:47 |
| soul-d | k then makes sense why azonenberg looks at sputtering :) | 17:51 |
| soul-d | btw you have glassblowers near you that make chemisty labware on design? cause i actually do have a few around me | 17:54 |
| superkuh | Me? I could probably find one at the state university that's 100m away from where I am sitting. But it's too expensive. | 18:03 |
| soul-d | heh true it would be expensive for custom stuff but this shops build chemistry labware and gassious lighting so they probably could make half sputtering thingy from the store | 18:08 |
| azonenberg | soul-d: A sputtering apparatus would only need a bell jar and a baseplate, both of which can be bought premade | 18:20 |
| azonenberg | the only custom work would be drilling holes in the base plate and inserting high-voltage feedthroughs | 18:20 |
| azonenberg | and sealing appropriately to hold vacuum | 18:20 |
| soul-d | mmm, don't forget im in tiny country only jar bell i found is cheap bottle looking one with no information | 18:28 |
| soul-d | http://www.labstuff.nl/contents/media/1g.jpg <- is large picture and looks just like a bottle to me :) | 18:29 |
| smeding | heh, labstuff | 18:35 |
| smeding | love that place though i do not have the money to buy stuff there | 18:35 |
| smeding | or enough interest, really, a lot of the time | 18:35 |
| soul-d | heh | 18:38 |
| soul-d | need some food bbl | 18:39 |
| azonenberg | lol | 18:41 |
| berndj | is the "snooker ball" model for calculating mean free path sorta sane for estimating the MFP of an electron in a gas? | 21:21 |
| azonenberg | Hmm, maybe? I'm not too familiar with electrostatic interactions | 21:22 |
| berndj | just thinking of how to bootstrap a high vacuum vessel | 22:01 |
| berndj | since apparently welds are really, really hard to make properly gas-tight | 22:02 |
| berndj | but if electrons can get far enough, why not use a big beam of those to suture up the crude weld from the inside? | 22:02 |
| azonenberg | Hmm, no idea | 22:11 |
| azonenberg | Never tried building a pressure vessel | 22:11 |
| azonenberg | always bought them | 22:11 |
| berndj | i'm pretty sure i can't afford one :) | 23:08 |
| soul-d | i thought id download macguyver to inspire me but it was dubbed in french :( | 23:09 |
| soul-d | otherwise id probably make one with an elastic band some tape and a coke can | 23:09 |
| azonenberg | lol | 23:09 |
| berndj | that was my favourite show when i was a kid. i DON'T want to see reruns now and ruin the memory | 23:09 |
| soul-d | true :) | 23:10 |
| soul-d | but din't see them all :P | 23:10 |
| azonenberg | Well right now I'm busy working on something unrelated to IC fab (yes, I do other things too :P) | 23:10 |
| azonenberg | FPGA switching fabric design :D | 23:10 |
| soul-d | although i have studied fpga a bit it doesn't tell me anything :P you mean the underlying tech to make the general logic ? | 23:11 |
| azonenberg | No | 23:12 |
| azonenberg | i mean a 16 port 12.8 Gbps-per-port switching fabric | 23:12 |
| azonenberg | to connect various elements on my SoC | 23:13 |
| soul-d | k, not that deep in designing yet so can't visualize it :P | 23:19 |
| azonenberg | It's basically the equivalent of a 16-port 10gbe switch | 23:19 |
| azonenberg | Except each packet is, instead of an ethernet frame, my own interconnect format | 23:20 |
| azonenberg | which includes source/dest port numbers (only one device allowed per port so no MAC addressing etc), 32 bits of address, a read/write bit, and 64 bits of data if it's a write | 23:21 |
| smeding | sounds fun | 23:22 |
| smeding | especially compared to what i'm doing | 23:22 |
| azonenberg | whats that? | 23:22 |
| smeding | horribly simplistic, horribly outdated ASIC design | 23:22 |
| azonenberg | oh, yeah you mentioned that | 23:22 |
| smeding | well, although we test it on an FPGA | 23:22 |
| azonenberg | the 2um SoG process? | 23:22 |
| soul-d | got some money think gonna check out the cheap pcb chemical | 23:23 |
| smeding | 1.6u but yeah | 23:23 |
| azonenberg | wanna bet your asic runs slower than the fpga version? :P | 23:23 |
| azonenberg | and lol, 1.6um is within the range of what i could be able to fab soon | 23:23 |
| smeding | no, that isn't a very fair bet | 23:23 |
| smeding | got ion diffusion down yet? p | 23:23 |
| smeding | :p | 23:23 |
| azonenberg | fair to the asic? | 23:23 |
| smeding | yeah | 23:23 |
| azonenberg | and i'm talking lithorgaphy | 23:23 |
| azonenberg | doping is one of the processes i havent looked at yet | 23:23 |
| smeding | anyway, we were basically told "don't expect the ASIC to work" | 23:24 |
| azonenberg | LOL | 23:24 |
| azonenberg | that bad? | 23:24 |
| smeding | between us being second-year EE undergrads and the people fabbing it being people who have never been in a clean room before | 23:24 |
| smeding | there is not a lot of yield | 23:24 |
| azonenberg | lolwut? | 23:24 |
| azonenberg | wow lol | 23:25 |
| smeding | they save money by having the clean room course consist of fabbing the ASIC for our project | 23:25 |
| smeding | i suppose | 23:25 |
| azonenberg | But still, lol | 23:25 |
| smeding | yeah it's pretty silly | 23:26 |
| smeding | the code some people put out is ridiculous though | 23:26 |
| smeding | i like to think what i wrote is reasonable, maybe even good VHDL | 23:26 |
| azonenberg | lol | 23:27 |
| azonenberg | i'm working on verilog but i'm still a relative novice | 23:27 |
| smeding | we have some dinky IR communications project, i wrote most of the IR subsystem and helped other groups | 23:27 |
| azonenberg | only written a few tens of thousands of lines total | 23:27 |
| smeding | one group wrote a module that receives ASCII and determines where it goes on the little LCD we hook up | 23:28 |
| smeding | from the IR decoder and the keyboard interface | 23:28 |
| azonenberg | Does it work on the FPGA? | 23:28 |
| smeding | nope | 23:28 |
| azonenberg | Lol | 23:29 |
| azonenberg | and you expect it to work on the asic? :P | 23:29 |
| smeding | i've given up hope | 23:29 |
| smeding | :p | 23:29 |
| azonenberg | lol | 23:29 |
| smeding | they claim they have fixed things though | 23:29 |
| azonenberg | The fab lab class in my school uses a single mask set that's probably ten years old | 23:29 |
| smeding | but looking at the design i don't see how anything short of a redesign could have fixed it | 23:29 |
| azonenberg | (i havent taken it) | 23:29 |
| azonenberg | But eevryone makes the same basic design | 23:29 |
| azonenberg | just some caps and transistors hooked up to probe pads | 23:29 |
| azonenberg | on a 2" wafer | 23:30 |
| smeding | ah | 23:30 |
| smeding | sounds reasonable | 23:30 |
| smeding | anyway, you should see the design plans for this module... they 'designed' a D flip-flop, used it to implement a register, used two of those and a multiplexer, and it's controlled by an icky half-state-machine | 23:31 |
| smeding | (the library comes with standard blocks and the synthesis engine is fairly intelligent) | 23:31 |
| azonenberg | lol | 23:32 |
| smeding | in their place i would just have made a big Moore machine and let the synth handle it | 23:32 |
| smeding | at least at first, maybe optimisation would require me to split it up | 23:32 |
| azonenberg | optimization? How slow is the current code? | 23:32 |
| smeding | oh, it's not slow enough to matter | 23:33 |
| smeding | the main limitation is chip size | 23:33 |
| azonenberg | oh lol | 23:33 |
| smeding | we can do 80k transistors max, and on SoG that's not that much | 23:33 |
| azonenberg | i'm used to optimizing for speed on a giant chip | 23:33 |
| azonenberg | and lol, 80k transistors? That's like what, 20k gates not even counting barrier transistors? | 23:33 |
| smeding | less, probably | 23:34 |
| azonenberg | So maybe 10k usable? | 23:34 |
| azonenberg | and i thought my 50k gate fpga was small | 23:35 |
| soul-d | i might have 50k if i add up all my fpga's :P | 23:36 |
| smeding | i still can't find where the 80k limit comes from though | 23:36 |
| soul-d | or difrent from le's ? :P | 23:37 |
| azonenberg | lol, yes | 23:37 |
| smeding | the manual says 200k but we were assured by the tutor the limit is 80k | 23:37 |
| azonenberg | a LUT is several gate equivalents | 23:37 |
| azonenberg | and a LE is usually several LUTs | 23:37 |
| smeding | anyway an inverter occupies 4 transistor positions | 23:38 |
| azonenberg | what about a 2NAND? | 23:38 |
| smeding | six | 23:38 |
| azonenberg | thats usually the definiteion of a gate-equiv | 23:38 |
| azonenberg | i see | 23:38 |
| smeding | then you add barrier transistors and wiring room | 23:39 |
| smeding | and you get efficiencies of something like 30% | 23:39 |
| smeding | in terms of transistors used for switching vs transistor positions occupied | 23:39 |
| smeding | so that's like, 6k gates? | 23:40 |
| azonenberg | lol | 23:41 |
| azonenberg | wow | 23:41 |
| smeding | the only groups who have a full design working on the FPGA have given up on trying to fit it onto the ASIC i think | 23:41 |
| azonenberg | lol | 23:42 |
| azonenberg | you could like barely fit a UART in that | 23:42 |
| smeding | hm, then i might be exagerrating | 23:42 |
| smeding | because we have a sort of UART, and more | 23:42 |
| smeding | well, it's not an UART... the receive portion is ugly, from what i've seen | 23:43 |
| azonenberg | Lol | 23:55 |
| azonenberg | well ok, you could fit a uart and change | 23:55 |
| azonenberg | But not too much | 23:55 |
| --- Fri Dec 23 2011 | 00:00 | |
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