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Your Own Open Source ASIC: SkyWater-PDF Plans First 130 nm Wafer in 2020



You might have caught Maya Posch’s article about the first open-source ASIC tools from Google and SkyWater Technology. It envisions increased access to make custom chips — Application Specific Integrated Circuits — designed using open-source tools, and made real through existing chip fabrication facilities. My first thought? How much does it cost to tape out? That is, how do I take the design on my screen and get actual parts in my hands? I asked Google’s Tim Ansel to explain some more about the project’s goals and how I was going to get my parts.

The goals are pretty straightforward. Tim and his collaborators would like to see hardware open up in the same way software has. The model where teams of people build on each other’s work either in direct collaboration or indirectly has led to many very powerful pieces of software. Tim’s had some success getting people interested in FPGA development and helped produce open tools for doing so. Custom ASICs are the next logical step.

Who Needs Open Source ASICs?

Of course, FPGAs and ASICs aren’t the answer to every problem. We can’t help but notice that some examples you see — including ours — are sometimes better for learning than actually practical. For example, the classic sample for learning about state machines on an FPGA is a traffic light. Why not? Everyone sort of understands what it is supposed to do, it has clear state logic, and you can make it as simple as you like or quite complex if it senses vehicles and pedestrian crosswalk buttons or changes based on schedules.

However, if you were really building a traffic light, it wouldn’t make a lot of sense to do it in an FPGA. Even the simplest microcontroller would be up to the task and would be cheaper both to buy and in terms of engineering costs by a wide margin.

ASICs occupy a similar niche, but with a little bit of a difference. On the plus side, they should be denser, faster, and less power hungry than a similar FPGA. That makes sense because the ASIC is sort of an FPGA where the interconnections are made with dedicated metal lines instead of being generally configurable. You can also put down exactly the circuits you want — or, at least, choose from a variety of cells instead of having to use whatever the FPGA’s architect decided you need. You can even include analog cells alongside digital circuitry.

On the negative side, ASICs are not for the sloppy. Historically, taping out an ASIC has been very expensive. So you have a run of parts but — oops — you forgot that counter needs to reset to a non-zero number. In an FPGA, that’s a minor annoyance; you simply change the configuration — especially now that one time programmable FPGAs are rare outside of certain applications. Even if you have to trash an FPGA and program another one, they are generally not very expensive unless they are radiation hardened or very large devices.

If you make that mistake on an ASIC, you are in big trouble. You can’t change anything on the parts you have. You have to have a new batch built with new upfront costs. In the commercial world, that kind of mistake can be career-ending.

Tim makes it clear that his target audience isn’t the professional building custom ASICs, though. It is us. The hackers and tinkerers that want to create custom ICs. There may be some student market, too, although schools often have deals to make that feasible already.

Tim does point out, though, that a lot of those school deals are bound up with nondisclosure agreements the students have to sign, so it’s possible that open tools will spur new published research which would be a good thing. Still, I get the sense they think most of the interest will be from our community.

Notable about this process is that the 130 nm process being used isn’t cutting edge technology. The Skywater Technologies fab was built by Cypress Semiconductor in 1991 in Bloomington, Minnesota. Tim says professional designers have moved so far from these large geometries that our designers may have to rediscover some lost knowledge along the way to get the most from an IC made on the larger processes now. But the existing infrastructure is a big part of what makes this project more affordable.

So How Do You Get Them?

Tim had a lot to say about cell libraries that are eminent and how each one was tuned for a different purpose (e.g., high density or low power or high speed). However, we wanted to know how we’d get actual parts. Apparently, some of the details or still being worked out.

Chip scale devices on a penny by Cp82 CC-BY-SA 3.0

In November, they plan to order a multiproject wafer with 40 slots. They don’t know yet if they will have to beg and plead to get 40 designs or if they will have to winnow the select down from all possible candidates. If you are one of the 40, you’ll get about 10mm square to play with and wind up with somewhere around 100 to 300 chips in chip-scale packaging (CSP). You can see a typical CSP sitting on a US penny in the accompanying photo.

There are a few stipulations. You’ll submit your design on GitHub (or some similar public repository), so your design is going to be open source. That means even if you aren’t one of the 40, you’ve just put your chip out for the world to see. The foundry will automatically check your design to meet certain technical criteria. At this early point there doesn’t seem to be a firm plan on how they will select designs for inclusion in the first run. Presumably, if there are a lot of entrants and things work well, there will be more wafers in 2021.

There are still a lot of unanswered questions. Can you pay to get your own tape out? If so, do you still have to be open source? What if you have some made and then want more? How much does that cost? This is very early and we do we not yet know the answers to these questions, but details will come together over time.

The Key

Like I said earlier, ASICs aren’t for everyone and they certainly aren’t for people who test and debug as they go. Verification is essential for a successful ASIC project. That means a lot of this will hinge on the simulation tools available and the quality of the models available. Spending a lot of time and money getting ICs that won’t work at the speeds you need, consume more power than you expected, or simply don’t work is heartbreaking.

Many times an FPGA can be used to validate some or all of your design before trying to go to an ASIC. When that works, it works well. However, because of the differences between the two technologies, it isn’t as simple as thinking of an ASIC as a fixed FPGA. You have the same problems you might have going from a hand-wired circuit to a PCB. Logically they are the same. But we all know you can have problems with that transition because of the different characteristics. It is the same problem here. How do you test your analog cells? Will the clock distribute the same? And ASICs have speed or power requirements which are difficult to mimic in a validation stage.

Tim Ansel gave an online talk today officially announcing the project. Take a look for more details on the process node itself and the tools used to design for it:

So will you try to design your own IC? I’ve been involved in ASIC development before, but I still might be interested in doing my own personal project just to be able to do all the steps. Let us know what IC you want to design — or see someone else design — in the comments.

Header image: Peellden/ CC BY-SA 3.0

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Technology reveals face behind 1,700-year-old Siberian death mask



The desk mask (left) and one scan of the face beneath it (right) (Siberian Times)

Russian scientists have used modern CT scanning technology to peer at the face of a man who died 1,700 years ago.

The man was aged between 25 and 30 when he died and was part of a tribe of cattle-breeders called the Tashtyk that lived in Siberia hundreds of years ago.

Like others of his tribe, the man was buried with a death mask covering his face.

Computed tomography scans, known as CT scans, use x-rays and computers to build up detailed pictures of the insides of our bodies. In this instance, researchers could peer behind the death mask without disturbing the mummy beneath.

They found hair worn in a pigtail fashion that would have been cut off before he was buried, and a scar running across the left side of his face.

CT scan of the skin and skull

A CT scan of the skull and the skin of the 1,700 year old man (The State Hermitage Museum)

He also had a big hole – perhaps 7 or 8cm long – in his temporal lobe which may have been to remove his brain before burial. Likewise, the scar appears to have been sewn up in a suture.

Despite this, the man appears to be resting peacefully in death with no signs of anguish in his expression.

‘They took all these postmortem rites very seriously, and did not save on this,’ explained Dr Svetlana Pankova, curator at the State Hermitage Museum, St Petersburg, and keeper of the Siberian collection of the Department of Archeology.

‘They could not just put a mask on the disfigured face,’ she told the Siberian Times.

Svetlana Pankova puts the male head into CT scaner

Svetlana Pankova puts the male head into CT scanner (The State Hermitage Museum)

‘Our research is complicated by the fact that we cannot take the mask away from the face (it would cause too much damage)  so we must research this stitching using other methods.’

Dr Pankova said the mask ‘has black stripes on a red background, plus the lower part of the mask was somewhat destroyed and man’s teeth can be seen. 

‘So all together it creates such an aggressive look.’

CT scan of the skin and skull with the scar and the trepanation hole visible

CT scan of the skin and skull with the scar and the trepanation hole visible (Credits: The State Hermitage Museum)

Yet under the mask ‘there was nothing aggressive in this face. It was the face of a calmly sleeping person.’

Dr Pankova added: ‘The computer scan allowed us to see, so to say, three layers – the layer of the mask, the layer of the face without the mask and layer of the skull.’


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Keyboard Shortcuts for Calendar, Reminders, and Notes on Mac



If you’re a Mac user looking for a simple and effective day planner, consider this trio of native macOS apps: Calendar, Reminders, and Notes.

Once you set up these apps to your liking, you have a fuss-free system to manage your schedule, tasks, and notes. Plus, if you learn how to control them with keyboard shortcuts, so much the better. And what’s more, you can discover various useful keyboard shortcuts for these macOS productivity apps in the cheat sheet below.

The cheat sheet contains shortcuts for navigation and search, view management, formatting, and more in Calendar, Reminders, and Notes.

FREE DOWNLOAD: This cheat sheet is available as a downloadable PDF from our distribution partner, TradePub. You will have to complete a short form to access it for the first time only. Download Keyboard Shortcuts for Calendar, Reminders, and Notes on Mac.

Keyboard Shortcuts for Calendar, Reminders, and Notes on Mac

Cmd + N Add new event
Option + Cmd + N Add new calendar
Shift + Cmd + N Add new calendar group
Option + Cmd + S Add new calendar subscription
Cmd + F Highlight search box to search for events
Cmd + 1 Switch to Day view
Cmd + 2 Switch to Week view
Cmd + 3 Switch to Month view
Cmd + 4 Switch to Year view
Cmd + Right Arrow Go to next day, week, month, or year
Cmd + Left Arrow Go to previous day, week, month, or year
Cmd + T Switch to today’s date
Shift + Cmd + T Open popup for switching to specific date
Cmd + + (Plus) Increase text size
Cmd + – (Minus) Decrease text size
Cmd + R Refresh all calendars
Cmd + E Edit selected event
Esc (when event is open) Close event editor without saving changes
Return (when event is open) Commit changes to event and close event editor
Cmd + I Show Info popup for selected event(s)
¹Option + Cmd + I Show Inspector popup for selected event
Arrow Keys Select event (if available) in adjacent row/column in relevant direction
Control + Option + Up Arrow Day/Week View: Move selected event 15 minutes earlier
Month View: Move selected event one week earlier
Control + Option + Down Arrow Day/Week View: Move selected event 15 minutes later
Month View: Move selected event one week later
Control + Option + Right Arrow Day/Week/Month View: Move selected event one day later
Control + Option + Left Arrow Day/Week/Month View: Move selected event one day earlier
Shift + Cmd + A Toggle Availability panel
Cmd + N Create new reminder
Shift + Cmd + N Create new list
²Cmd + ] Indent reminder to create subtask
²Cmd + [ Outdent reminder
Cmd + E Show all subtasks
Shift + Cmd + E Hide all subtasks
³Cmd + I Show Info popup for selected reminder
Cmd + F Highlight search box to search for reminders
²Shift + Cmd + F Set/clear flag for selected reminder(s)
Control + Cmd + S Toggle sidebar
Cmd + N Create new note
Shift + Cmd + N Create new folder
Shift + Cmd + A Open dialog for attaching file
Cmd + K Create link
Cmd + F Highlight search box to search current note
Cmd + G Highlight next search result in current note
Shift + Cmd + G Highlight previous search result in current note
Option + Cmd + F Highlight search box to search all notes
Shift + Cmd + T Apply Title format
Shift + Cmd + H Apply Heading format
Shift + Cmd + J Apply Subheading format
Shift + Cmd + B Apply Body format
Shift + Cmd + M Apply Monospaced format
Shift + Cmd + L Apply Checklist format
Shift + Cmd + U Mark selected checklist items as checked/unchecked
Control + Cmd + Up Arrow Move current list/checklist item up in list
Control + Cmd + Down Arrow Move current list/checklist item down in list
Cmd + B Emphasize selected text
Cmd + I Italicize selected text
Cmd + U Underline selected text
Cmd + + (Plus) Increase size of selected text
Cmd + – (Minus) Decrease size of selected text
Cmd + Shift + [ Align selected text flush left
Cmd + Shift + Center selected text
Cmd + Shift + ] Align selected text flush right
Cmd + [ Decrease indent level of selected content or line where cursor is placed
Cmd + ] Increase indent level of selected content or line where cursor is placed
Control + Return Add line break (soft return) to list/checklist item
Option + Tab Insert tab character in list item
Option + Cmd + C Copy style of selection
Option + Cmd + V Paste copied style to selection
Cmd + T Show Fonts window
Shift + Cmd + C Show Colors window
Option + Cmd + T Create table
⁴Return Move cursor to row below
Tab Move focus to next cell on right
Shift + Tab Move focus to next cell on left
Shift + Left/Right Arrow Select cells one by one in relevant direction current row
Shift + Up/Down Arrow Select cells one by one in relevant direction in current column
Option + Return Add new paragraph in current cell
Option + Tab Add tab character in current cell
Option + Cmd + Up Arrow Add new row above current row
Option + Cmd + Down Arrow Add new row below current row
Option + Cmd + Right Arrow Add new column to right of current column
Option + Cmd + Left Arrow Add new column to left of current column
Cmd + 0 Show main Notes window
Cmd + 1 Switch to List view for notes
Cmd + 2 Switch to Gallery view for notes
Cmd + 3 Switch to Attachments Browser
Return (when note is selected in List view or Gallery view) Open or switch focus to selected note to begin typing
Cmd + Return Open or switch focus from current note content to previous notes view i.e. List view or Gallery view
Option+ Cmd + S Toggle Folders sidebar
Shift + Cmd + . (Period) Zoom in on note content
Shift + Cmd + , (Comma) Zoom out of note content
Shift + Cmd + 0 Change note content to default size
⁵Cmd + A (When cursor is in table) Select content of active cell OR
Select table if active cell is empty
Common Shortcuts
Cmd + Z Undo previous action
Shift + Cmd + Z Reverse undo
Cmd + X Cut selected item
Cmd + C Copy selected item
Cmd + V Paste cut/copied item
Delete Delete selected item
Cmd + A Select all items
Cmd + P Open Print dialog
Cmd + , (Comma) Open app preferences
Control + Cmd + F Toggle Full Screen mode
Cmd + M Minimize window
Option + Cmd + M Minimize all windows of current app
⁶Cmd + W Close current window
Option + Cmd + W Close all windows of current app
Cmd + H Hide current app
Option + Cmd + H Hide all apps except current app
Cmd + Q Quit app
¹Shortcut does not work with multiple events, but if you switch between events when Inspector is active, its contents are updated accordingly.

²Shortcut may not be available if iCloud is not enabled.

³If multiple reminders are selected, Info popup for last selected reminder is displayed.

⁴If cursor is in last row, shortcut adds new row to table.

⁵When active cell is populated, press shortcut twice to select table.

⁶In Reminders and Notes, shortcut quits app after closing window.

Bullet Journaling With Mac Productivity Apps

The default productivity apps on macOS are not only easy to use, but also quite flexible. You can use them to bring offline note-taking methods online. For example, you can create a Bullet Journal on your Mac with Calendar, Reminders, or Notes.

Image Credit: Colton Sturgeon on Unsplash

Read the full article: Keyboard Shortcuts for Calendar, Reminders, and Notes on Mac

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If the coronavirus is really airborne, we might be fighting it the wrong way



This was the week airborne transmission became a big deal in the public discussion about covid-19. Over 200 scientists from around the world cosigned a letter to the World Health Organization urging it to take seriously the growing evidence that the coronavirus can be transmitted through the air. WHO stopped short of redefining SARS-CoV-2 (the virus that causes covid-19) as airborne but did acknowledge that more research is “urgently needed to investigate such instances and assess their significance for transmission of COVID-19.”

“I honestly don’t know what people are waiting for,” says microbiologist Chad Roy of Tulane University in the US. “It doesn’t take WHO coming out to make a proclamation that it’s airborne for us to appreciate this is an airborne disease. I don’t know how much clearer it needs to be in terms of scientific evidence.” 

So what does “airborne” really mean in this context? It’s basically an issue of size. We’re pretty sure that SARS-CoV-2 is spread through tiny droplets that contain viral particles capable of leading to an infection. For a virus to be airborne, however, means a few different things, depending on the expert you’re talking to. Typically it means it can spread via inhalation over long distances, perhaps even through different rooms, of small particles known as aerosols.

“That’s why when you ask some of the professionals if the virus is airborne, they’ll say it’s not, because we’re not seeing transmission over those sorts of distances,” says Lisa Brosseau, a retired professor of public health who still consults for businesses and organizations.

There is also some debate on what we mean by “aerosol.” The droplets that carry viral particles through the air can come in all sorts of sizes, but while the larger ones will drop quickly to the ground or other surfaces, the smaller ones (just a few microns across) can linger in the air for a while, giving them a chance to be inhaled. The word is mostly used to describe these smaller particles, although Brosseau would prefer the term “aerosol transmission” to cover the entire gamut of inhalable viral particles being expelled into the air—large and small alike. 

If SARS-CoV-2 is airborne, it’s far from the only disease. Measles is notorious for being able to last in the air for up to two hours. Tuberculosis, though a bacterium, can be airborne for six hours, and Brosseau suggests that coronavirus superspreaders (people who seem to eject a larger amount of the virus than others) disseminate the virus in patterns that recall the infectiousness of tuberculosis.

The evidence that this type of transmission is happening with SARS-CoV-2  arguably already exists. Several big studies point to airborne transmission of the virus as a major route for the spread of covid-19. Other studies have suggested the virus can remain in aerosolized droplets for hours. One new study led by Roy and his team at Tulane shows that infectious aerosolized particles of SARS-CoV-2 could actually linger in the air for up to 16 hours, and maintain infectivity much longer than MERS and SARS-CoV-1 (the other big coronaviruses to emerge this century). 

We still don’t know what gives SARS-CoV-2 this airborne edge. “But it may be one reason this is a pandemic, and not simply a small outbreak like any other coronavirus,” says Roy. 

How to stay safe

Whether the virus is airborne isn’t simply a scientific question. If it is, it could mean that in places where the virus has not been properly contained (e.g., the US), the economy needs to be reopened more slowly, under tighter regulations that reinforce current health practices as well as introducing improved ones. Our current tactics for stopping the spread won’t be enough.

Roy would like to see aggressive mandates on strict mask use for anyone leaving home. “This virus sheds like crazy,” he says. “Masking can do an incredible amount in breaking transmission. I think anything that can promote the use of masking, to stop the production of aerosols in the environment, would be helpful.” 

Brosseau, however, says that though masks can limit the spread of larger particles, they are less helpful for smaller ones, especially if they fit only loosely. “I wish we would stop relying on the idea that face coverings are going to solve everything and help flatten the curve,” she says. “It’s magical thinking—it’s not going to happen.” For masks to really make a difference, they would need to be worn all the time, even around family.

Brosseau does believe the evidence is trending toward the conclusion that airborne transmission is “the primary and possibly most important mode of transmission for SARS-CoV-2.” She says, “I think the amount of time and effort devoted to sanitizing every single surface over and over and over again has been a huge waste of time. We don’t need to worry so much about cleaning every single surface we touch.” Instead, the focus should be on other factors, like where we spend our time.

Crowded spaces

One of the biggest questions we still have about covid-19 is how much of a viral load is needed to cause infection. The answer changes if we think it is aerosols that we need to worry about. Smaller particles won’t carry as large a viral load as bigger ones, but because they can linger in the air for much longer, it may not matter—they’ll build up in larger concentrations and get distributed more widely the longer an infected person is around to expel aerosolized virus. 

The more people you have coming in and out of an indoor space, the more likely it is that someone who is infected will show up. The longer those infected individuals spend in that space, the higher the concentration of virus in the air over time. This is particularly bad news for spaces where people congregate for hours on end, like restaurants, bars, offices, classrooms, and churches. 

Airborne transmission doesn’t necessarily mean these places must stay closed (although that would be ideal). But wiping down surfaces with disinfectant, and having everyone wear masks, won’t be enough. To safely reopen, these spots will not just need to reduce the number of people allowed inside at any given moment; they will also need to reduce the amount of time those people spend there. Increasing social distancing beyond six feet would also help keep people safer. 

Ventilation needs to be a higher priority too. This is going to be a big problem for older buildings that usually have worse ventilation systems, and areas with a lot of those might need to remain closed for much longer. The impact of asymptomatic spread (transmission by people who don’t feel ill) and superspreaders only compounds the problem even further. But research conducted by the US Department of Homeland Security has shown that in the presence of UV light, aerosolized particles of the size the Tulane researchers studied would disappear in less than a minute. A number of businesses have begun deploying UV-armed robots to disinfect hospital rooms, shopping malls, stores, public transit stations, and more.

For many places, considerable delays in economic reopening might ultimately be the price of getting the virus under control. Otherwise the kind of thing that happened when a single open bar in Michigan led to an outbreak of more than 170 new cases could become commonplace. 

For Brosseau, the best strategy is simply to behave as we did in the early days of lockdown—stay home, and avoid coming into contact with anyone you don’t live with. And if you have to leave home, she says, “all I can say is spend as little time as possible in an enclosed space, in an area that’s well ventilated, with as few people as possible.”

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