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<
bart416>
^you should totally try to gravedig that thread :')
<
bart416>
Also, any suggestions for a transistor level flank triggered D latch?
<
bart416>
*rising edge
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<
smeding>
hahaha that thread
<
smeding>
bart416: do you need a schematic? i can rip one from a book of mine
<
bart416>
smeding, anything is welcome :P
<
bart416>
My design is not that uhm, great :p
<
bart416>
Uses way too much transistors in my opinion
<
smeding>
eh, latches use a fair bunch of them usually
<
bart416>
Too much heh :P
<
smeding>
the one here uses 22 transistors
<
smeding>
let me see what the actual SoG implementation for our uni project does
<
bart416>
well, if you're going VLSI or better it's not much of an issue if it works fast
<
bart416>
The thing is, I don't want to be using 160 transistors per 8 bit word
<
smeding>
do you want one with a reset
<
smeding>
and if so, sync or async?
<
bart416>
that doesn't matter that much actually
<
smeding>
i'll take a picture
<
smeding>
that's an implementation that's actually used
<
smeding>
it's for a 1.6u SoG process though, hehe
<
smeding>
but i don't think it should matter all that much
<
bart416>
Urgh, I'm using BJTs :P
<
bart416>
I have enough books on CMOS design to build a desk out of them by now I think
<
smeding>
well you should have mentioned that :p
<
smeding>
i don't have any books on TTL or anything
<
bart416>
It's RTL as well :P
<
bart416>
TTL is tricky in discrete components for reasons I'm so not getting into lol
<
bart416>
I'll leave it at you're quite often largely dependent on somewhat similar hFEs
<
bart416>
I can't count on that
<
bart416>
I'm using 2N3904 bjts in my design
<
bart416>
so min hFE is about a hundred
<
bart416>
It should work as long as hFE stays above 50 or so
<
azonenberg>
Well you're also dependent on multi-emitter transistors if you build them the classic way
<
azonenberg>
I like CMOS
<
azonenberg>
And I want to build it :p
<
bart416>
BJT is cheaper and actually faster in this case
<
azonenberg>
Something as complex as a FF might take a while to be able to make
<
bart416>
It's easier to design a "high speed" BJT circuit than a MOS one
<
azonenberg>
I do wonder if Jeri's process would work with BJTs
<
azonenberg>
Because I have a pretty good idea of how to do a home MOS process
<
azonenberg>
I actually want to try prototyping a CD4000 series chip on a PCB with discrete FETs
<
azonenberg>
make sure i have the circuit right
<
azonenberg>
Using a standard-cell based design
<
azonenberg>
But actual fab is still a ways out
<
azonenberg>
I want to do a comb drive soon
<
azonenberg>
Just have to find the time to actually work on it ;p
<
azonenberg>
And make a new spin coater controller
<
bart416>
Best I've got right now is actually the very old trustworthy digital design, replace gates with transistor equivalents
<
bart416>
that'll do it with 18 transistors
<
bart416>
I fear I'll have to switch my design to 4 bit
<
azonenberg>
bart416: I would not attempt anything more complex than a single CD4000 chip
<
azonenberg>
until you have VLSI down well
<
bart416>
I'm building discrete...
<
azonenberg>
... oh
<
bart416>
That's why I'm worried about transistor count
<
bart416>
I don't give a damn about speed at this point actually
<
bart416>
I'm happy with 1kHz in fact
<
bart416>
My current method should alllow me to go past 100 kHz though!
<
azonenberg>
Very nice
<
azonenberg>
Btw, I was just thinking
<
azonenberg>
I can hit 12um on a film mask
<
azonenberg>
design rule
<
azonenberg>
if i feed that into 10x reduction thats 1.2um design rules
<
azonenberg>
On an area about 1.6mm across
<
azonenberg>
Which should be enough to actually build something of useful complexity
<
azonenberg>
I think some time in the next week-ish i am going to try making a flip chip BGA
<
azonenberg>
Something of trivial complexity, not even projection litho
<
bart416>
If you do that you might be able to get some donations (to buy new equipment)...
<
azonenberg>
just contact at few-hundred-micron feature sizes
<
azonenberg>
IOW an inert packaging dummy
<
azonenberg>
but if i can conduct a signal from balls A1 to A2, B1 to B2, C1 to C2
<
azonenberg>
and not short between the pairs
<
azonenberg>
That will tell me the packaging technique is sound
<
bart416>
and you won't need to be nearly as careful at those feature sizes...
<
azonenberg>
The goal is to build a FCBGA in an amateur process
<
bart416>
and you could make 7400 series ICs already
<
azonenberg>
Even if the device is inert
<
azonenberg>
And i cant do 7400 yet
<
azonenberg>
i dont have dopants
<
azonenberg>
or a furnace
<
azonenberg>
I mean, my litho is good enough
<
azonenberg>
I just have to get the other tools
<
azonenberg>
its probably a few more months of work
<
azonenberg>
i'm right on the edge
<
bart416>
I guess I'll just ask a professor about it tomorrow
<
bart416>
btw, I pissed somebody off at an auction yesterday evening azonenberg
<
bart416>
I did a Google
<
azonenberg>
explain?
<
bart416>
Was placing bids based on physical and mathematical constants :P
<
azonenberg>
I approve strongly
<
bart416>
So did the fellow engineering students that were there, sadly we weren't in charge of the auction :P
<
bart416>
So the polsoc major that was doing it got pissed cause he couldn't remember the numbers we were throwing at him
<
bart416>
ok, in his defence he might not know that the square root of pi is 1.772454
<
bart416>
But that's no excuse to suck that much :P
<
azonenberg>
sqrt(pi)?
<
azonenberg>
Why not sqrt(2)
<
azonenberg>
1.414 ish
<
azonenberg>
or were you trying to beat 1.50
<
bart416>
Well, multiplied by 10 that is :P
<
bart416>
So 17.72 euro was our bid lol
<
bart416>
ofc we were shouting "TEN TIMES THE SQUARE ROOT OF PI"
<
bart416>
Actually, that might have been why they kicked us out halfway
<
bart416>
Well, two reasons
<
bart416>
1) We were buying everything
<
bart416>
2) We were being assholes
<
bart416>
3) Constant math jokes
<
bart416>
Number 3 not being a real reason to get kicked out
<
bart416>
(Number 1 is problematic cause it's for some good goal and they were auctioning dinner seats :P )
<
bart416>
But we bought the entire table of 20 people with 7 xD
<
bart416>
well yeah, 20 pairs of people I meant sorry
<
bart416>
Considering most of us don't even have a relationship we'll take up 40 places with 7 people
<
bart416>
And that all for the price of 173.8 euro in total...
<
bart416>
Considering the restaurant it's a bargain lol
<
bart416>
The polsoc idiot also managed to sell his own bike without realising it :')
<
bart416>
One of his "friends" put it in between the items
<
bart416>
And it was described on the list as "bicycle, used"
<
azonenberg>
Dummkopf :p
<
azonenberg>
What'd you buy it for
<
bart416>
And he was too lazy to bring it up to the stage so he never noticed it
<
bart416>
Nah, we didn't buy it
<
bart416>
We didn't know it was his bicycle until the "friend" in question told us
<
bart416>
I'll just leave it at, it went cheap
<
bart416>
There were some nice items though
<
bart416>
Several rare books
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