- Libresilicon-developers - libresilicon.com

Meeting today: Legal lithography
by David Lanzendörfer 15 Aug '21

15 Aug '21

Howdy So I suggest, now that we came to the conclusion that I should really follow the law in a broader sense when it comes to developers and resists, and etching, I decided to go Sam's route and use AZ 4210 with KOH as developer and run a magnetron design from Hack A Day in reverse for the etching process. Lets discuss that :-) -- (\__/) (='.'=) This is Ninja Bunny. (")_(") Copy and paste Bunny into your signature to help him gain world domination

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Uncertainty: DMD chips and 420nm
by David Lanzendörfer 15 Aug '21

15 Aug '21

Hi Dilek, hi list Sorry again about the downtime of the infrastructure during the day yesterday. The infrastructure of the data center I've got my rack server in was down. Now to the topic: I've started writing down the BOM and I'm not sure whether 420 nm UV already has too much energy, although the data sheet of the DMD chip says it's ok to be operated until 400nm. Here's the BOM: https://redmine.libresilicon.com/projects/maskless-lithography/wiki It would be cool to get feedback on that from Texas Instruments. Cheers David -- (\__/) (='.'=) This is Ninja Bunny. (")_(") Copy and paste Bunny into your signature to help him gain world domination

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Libresilicon infrastructure down
by Ferenc Éger 10 Aug '21

10 Aug '21

Hello David, Sorry for the spam. It seems that Libresilicon infrastructure is down. All machines in 62.192.20.131-136 are unresponsive and unpingable. Also, I get "Nameserver c.ns.buddyns.com. reports: No such host dns.lanceville.cn". Regards, Ferenc

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Announcement - Mumble session on Sunday 2021-08-08 @ 18:00 UTC
by Hagen SANKOWSKI 09 Aug '21

09 Aug '21

Hello List! This is our weekly announcement for the next Mumble Sessions on Sunday 2021-08-08 @ 18:00 UTC. Please join us as usual at our Mumble Server murmur.libresilicon.com at Port 64738, the Channel is IC. We like to follow-up our topics from mumble sessions before. Regards, Hagen.

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Precision leadscrews
by David Lanzendörfer 03 Aug '21

03 Aug '21

Hello everyone So I've been checking for affordable precision leadscrews for positioning the table and came across this web shop here: https://shop.mitutoyo.eu/web/mitutoyo/en/mitutoyo/01.02.07.04/ Precision%20Lead%20Screw/$catalogue/mitutoyoData/PR/04AZA161/index.xhtml What do you think? -- (\__/) (='.'=) This is Ninja Bunny. (")_(") Copy and paste Bunny into your signature to help him gain world domination

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Maskless lithography
by David Lanzendörfer 02 Aug '21

02 Aug '21

Howdy So I came across those two components which can solve our positioning problem with the wafer: Those LEDs produce a light within the spectrum we need in order to shine through silicon (1000nm ~ 1400nm): https://tech-led.com/en/product/ir-nir-leds/ The OV5647 is sensible up to at least 1000 nm and is quite affordable: https://cdn.sparkfun.com/datasheets/Dev/RaspberryPi/ov5647_full.pdf There are OV5647 imaging modules available for Raspberry Pi. I'll try to contact Marubemi directly and ask them for a quotation on their NIR/IR LEDs in the wavelength range we require and while I'm on it, I'll also check with them for a potentially more suitable CMOS sensor, then I'll compare the prices. As I've discussed with Dilek, the goal is to produce an affordable stepper suitable for hobbyists and small labs with limited budget. Cheers David -- (\__/) (='.'=) This is Ninja Bunny. (")_(") Copy and paste Bunny into your signature to help him gain world domination

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Announcement - Mumble session on Sunday 2021-08-01 @ 18:00 UTC
by Hagen SANKOWSKI 01 Aug '21

01 Aug '21

Hello List! This is our weekly announcement for the next Mumble Sessions on Sunday 2021-08-01 @ 18:00 UTC. Please join us as usual at our Mumble Server murmur.libresilicon.com at Port 64738, the Channel is IC. We like to follow-up our topics from mumble sessions before. Regards, Hagen.

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Announcement - Mumble session on Sunday 2021-07-18 @ 18:00 UTC
by Hagen SANKOWSKI 24 Jul '21

24 Jul '21

Hello List! This is our weekly announcement for the next Mumble Sessions on Sunday 2021-07-18 @ 18:00 UTC. Please join us as usual at our Mumble Server murmur.libresilicon.com at Port 64738, the Channel is IC. We like to follow-up our topics from mumble sessions before. Regards, Hagen.

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Re: [Libre-silicon-devel] Announcement - Mumble session on Sunday 2021-07-18 @ 18:00 UTC
by David Lanzendörfer 20 Jul '21

20 Jul '21

Someone successfully hooked up an Atmega MCU without differential gates (and so) to a DDR interface and got the DRAM chip to do something useful. You can also just use two IO pins instead of a differential gate, you just have to keep the transfer rates low enough, then you don't even need to tinker around with pull up and pull down resistors for compensating for the I/O pad resistance :-) Cheers -lev On Tuesday, July 20, 2021 9:18:35 AM WEST Hagen SANKOWSKI wrote: > Hello David. > > Long time ago, I had to connect an Altera FPGA with a DDR2 RAM. > It was a mess, do to an on-chip bug :-( > > BTW, as I still remember, at least a couple of signals are differential, > eg. Clock (CKx) and Data Select (DQSx), and needing balanced routing.. > > Sorry. > Hagen. > --- > "They who can give up essential liberty to obtain a little temporary > safety, deserve neither liberty nor safety." Benjamin Franklin (1775) > > Am 19.07.2021 16:06 schrieb David Lanzendörfer: > > DRAM DDR3 without leveling IS an option. > > We don't need special pads and can just use the I/O pads :-) > > > > https://www.intel.com/content/dam/altera-www/global/ja_JP/pdfs/literature/ > > an/ an520.pdf > > > > There we go! =^_^=~~~~~ > > > > On Sunday, July 18, 2021 8:51:41 PM WEST Hagen SANKOWSKI wrote: > >> Meeting Minutes of the Mumble session today > >> =========================================== > >> > >> Participants: Devon, tatzelbrumm (partly), hsank, leviathan > >> > >> > >> Topics > >> ------ > >> > >> - (external) RAM > >> > >> While thinking about an RISC-V CPU demonstrator, we need memory for > >> loading an Operating System like Linux. > >> > >> Our first guess was for the demonstrator just to use external RAM > >> chips, > >> e.g. with HyperRAM, which has a quite simple interface and can be > >> driven > >> without LVDS-IO-Pads (which are still not available for us). > >> Unfortunately using a couple of them gets fast quite expansive. > >> > >> Using commercial available (and cheaper) DRAM nowadays is out of reach > >> for us - this chips using a proprietary interface called DDR2 or DDR3. > >> This interface needs differential IO-Pads (the LVDS we already > >> mentioned > >> above) and is critical about timing (in the meaning of different wire > >> length, wire resistance and so on). > >> > >> Without a PDK for a technology we can not design the analog stuff > >> inside > >> 'cause we still miss all the concrete values for the layers to > >> calculate > >> transistor and wire sizes. > >> > >> - alternative: internal hand-crafted RAM-cells > >> > >> Designing internal RAM cells, no matter whether dynamic RAM or static > >> RAM isn't possible without the analog values from the PDK.. > >> > >> - possible pathes to go > >> > >> * Reducing the Operating System to smaller memory footprints (e.g. > >> with > >> NetBSD) and soldering a reasonable amount of HyperRAM close to the CPU > >> > >> * Getting a PDK and design with a couple of iterations in silicon our > >> analog stuff (LVDS-IO-Pads or RAM-cells hand-crafted) 'till it works.. > >> > >> '''' > >> Note: if we'd start with an alien PDK we had to re-design the analog > >> stuff from ground up again for our LibreSilicon PDK again.. > >> '''' > >> > >> If you have some suggestions how to get out of our > >> chicken-and-egg-Problem, please drop us an email :-) > >> > >> > >> Regards, > >> Hagen > >> _______________________________________________ > >> Libresilicon-developers mailing list > >> Libresilicon-developers(a)list.libresilicon.com > >> https://list.libresilicon.com/mailman/listinfo/libresilicon-developersH -- (\__/) (='.'=) This is Ninja Bunny. (")_(") Copy and paste Bunny into your signature to help him gain world domination

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Fwd: Announcement - Mumble session on Sunday 2021-07-18 @ 18:00 UTC
by Christoph Maier 17 Jul '21

17 Jul '21

Oops, forgot to forward to the group. In all fairness to the neuromorphs, they kept one more slide in the deck, but they moved it all the way to the end and didn't present it. https://docs.google.com/presentation/d/1El7U_EbFTuB5D5w-drW5fdWDpSrf05OthE9… tatzelbrumm ---------- Forwarded message --------- From: Christoph Maier <christoph.maier(a)ieee.org> Date: Sat, Jul 17, 2021 at 5:20 PM Subject: Re: [Libre-silicon-devel] Announcement - Mumble session on Sunday 2021-07-18 @ 18:00 UTC To: Hagen SANKOWSKI <hsank(a)posteo.de> Now that the Telluride Neuromorphic Workshop is over, where I just played with my Märklin train on the public record: https://youtu.be/3X-5Q-h6qjY?t=6502 I need to pay attention to what you're doing again ... in particular how far you are with getting skywater-pdk to work. What I did for the Telluride crowd wasn't considered very presentable. Of the stuff I did: https://github.com/MastellaM/sky130_TAC3/pull/3 only one slide made it into The Final Presentation: https://youtu.be/3X-5Q-h6qjY?t=2207 , and it was considered somewhat out of place. tatzelbrumm On Sat, Jul 17, 2021 at 12:49 PM Hagen SANKOWSKI <hsank(a)posteo.de> wrote: > > Hello List! > > This is our weekly announcement for the next Mumble Sessions on Sunday > > 2021-07-18 @ 18:00 UTC. > > Please join us as usual at our Mumble Server murmur.libresilicon.com at > Port 64738, the Channel is IC. > > We like to follow-up our topics from mumble sessions before. > > Regards, > Hagen. > _______________________________________________ > Libresilicon-developers mailing list > Libresilicon-developers(a)list.libresilicon.com > https://list.libresilicon.com/mailman/listinfo/libresilicon-developers

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