Design Resources: USB 3.1 and Type-C

By: Chris A. Ciufo, Editor, Embedded Systems Engineering

An up-to-date quick reference list for engineers designing with Type-C.

USB 3.1 and its new Type-C connector are likely in your design near-future. USB 3.1 and the Type-C connector run at up to 10 Gbps, and Type-C is the USB-IF’s “does everything” connector that can be inserted either way (and never is upside down). The Type-C connector also delivers USB 3.1 speeds plus other gigabit protocols simultaneously, including DisplayPort, HDMI, Thunderbolt, PCI Express and more.

Also new or updated are the Battery Charging (BC) and Power Delivery (PD) specifications that provide up to 100W of charge capability in an effort to eliminate the need for a drawer full of incompatible wall warts.

If you’ve got USB 3.1 “SuperSpeed+” or the Type-C connector in your future, here’s a recent list of design resources, articles and websites that can help get you up to speed.

Start Here: The USB Interface Forum governs all of these specs, with lots of input from industry partners like Intel and Microsoft. USB 3.1 (it’s actually Gen 2), Type-C, and PD information is available via the USB-IF and it’s the best place to go for the actual details (note the hotlinks). Even if you don’t read them now, you know you’re going to need to read them eventually.

“Developer Days” The USB-IF presented this two-day seminar in Taipei last November 2015. I’ve recently discovered the treasure trove of preso’s located here (Figure 1). The “USB Type-C Specification Overview” is the most comprehensive I’ve seen lately.

Figure 1: USB-IF held a “Developer Days” forum in Taipei November 2015. These PPT’s are a great place to start your USB 3.1/Type-C education. (Image courtesy: USB-IF.org.)

Figure 1: USB-IF held a “Developer Days” forum in Taipei November 2015. These PPT’s are a great place to start your USB 3.1/Type-C education. (Image courtesy: USB-IF.org.)

What is Type-C? Another decent 1,000-foot view is my first article on Type-C: “Top 3 Essential Technologies for Ultra-mobile, Portable Embedded Systems.” Although the article covers other technologies, it compares Type-C against the other USB connectors and introduces designers to the USB-IF’s Battery Charging (BC) and Power Delivery (PD) specifications.

What is USB? To go further back to basics, “3 Things You Need to Know about USB Switches” starts at USB 1.1 and brings designers up to USB 3.0 SuperSpeed (5 Gbps). While the article is about switches, it also reminds readers that at USB 3.0 (and 3.1) speeds, signal integrity can’t be ignored.

USB Plus What Else? The article “USB Type-C is Coming…” overlays the aforementioned information with Type-C’s sideband capabilities that can transmit HDMI, DVI, Thunderbolt and more. Here, the emphasis is on pins, lines, and signal integrity considerations.

More Power, Scotty! Type-C’s 100W Power Delivery sources energy in either direction, depending upon the enumeration sequence between host and target. Components are needed to handle this logic, and the best source of info is from the IC and IP companies. A recent Q&A we did with IP provider Synopsys “Power Where It’s Needed…” goes behind the scenes a bit, while TI’s E2E Community has a running commentary on all things PD. The latter is a must-visit stop for embedded designers.

Finally, active cables are the future as Type-C interfaces to all manner of legacy interfaces (including USB 2.0/3.0). At last year’s IDF 2015, Cypress showed off dongles that converted between specs. Since then, the company has taken the lead in this emerging area and they’re the first place to go to learn about conversions and dongles (Figure 2).

Figure 2: In the Cypress booth at IDF 2015, the company and its partners showed off active cables and dongles. Here, Type-C (white) converts to Ethernet, HDMI, VGA, and one more I don’t recognize. (Photo by Chris A. Ciufo, 2015.)

Figure 2: In the Cypress booth at IDF 2015, the company and its partners showed off active cables and dongles. Here, Type-C (white) converts to Ethernet, HDMI, VGA, and one more I don’t recognize. (Photo by Chris A. Ciufo, 2015.)

Evolving Future: Although USB 3.1 and the Type-C connector are solid and not changing much, IC companies are introducing more highly integrated solutions for the BC, PD and USB 3.1 specifications plus sideband logic. For example, Intel’s Thunderbolt 3 uses Type-C and runs up to 40 Gbps, suggesting that Type-C has substantial headroom and more change is coming. My point: expect to keep your USB 3.1 and Type-C education up-to-date.

Intel Changes Course–And What a Change!

By Chris A. Ciufo, Editor, Embedded Intel Solutions

5 bullets explain Intel’s recent drastic course correction.

Intel CEO Brian Krzanich (Photo by author, IDF 2015.)

Intel CEO Brian Krzanich (Photo by author, IDF 2015.)

I recently opined on the amazing technology gifts Intel has given the embedded industry as the company approaches its 50th anniversary. Yet a few weeks later, the company released downward financials and announced layoffs, restructurings, executive changes and new strategies. Here are five key points from the recent news-storm of (mostly) negative coverage.

1. Layoffs.

Within days of the poor financial news, Intel CEO Brian Krzanich (“BK”) announced that 12,000 loyal employees would have to go. As the event unfolded over a few days, the pain was felt throughout Intel: from the Oregon facility where its IoT Intelligent Gateway strategy resides, to its design facilities in Israel and Ireland, to older fabs in places like New Mexico. Friends of mine at Intel have either been let go or are afraid for their jobs. This is the part about tech—and it’s not limited to Intel, mind you—that I hate the most. Sometimes it feels like a sweatshop where workers are treated poorly. (Check out the recent story concerning BiTMICRO Networks, which really did treat its workers poorly.)

2. Atom family: on its way out. 

This story broke late on the Friday night after the financial news—it was almost as if the company hadn’t planned on talking about it so quickly. But the bottom line is that the Atom never achieved all the goals Intel set out for it: lower price, lower power and a spot in handheld. Of course, much is written about Intel’s failure to wrest more than a token slice out of ARM’s hegemony in mobile. (BTW: that term “hegemony” used to be applied to Intel’s dominance in PCs. Sigh.) Details are still scant, but the current Atom Bay Trail architecture works very nicely, and I love my Atom-based Win8.1 Asus 2:1 with it. But the next Atom iteration (Apollo Lake) looks like the end of the line. Versions of Atom may live on under other names like Celeron and Pentium (though some of these may also be Haswell or Skylake versions).

3. New pillars announced.

Intel used to use the term “pillars” for its technology areas, and BK has gone to great lengths to list the new ones as: Data Center (aka: Xeon); Memory (aka: Flash SSDs and the Optane, 3D XPoint Intel/Micro joint venture); FPGAs (aka: Altera, eventually applied to Xeon co-accelerators); IoT (aka: what Intel used to call embedded); and 5G (a modem technology the company doesn’t really have yet). Mash-ups of these pillars include some of the use cases Intel is showing off today, such as wearables, medical, drones (apparently a personal favorite of BK), RealSense camera, and smart automobiles including self-driving cars. (Disclosure: I contracted to Intel in 2013 pertaining to the automotive market.)

 Intel’s new pillars, according to CEO Brian Krzanich. 5G modems are included in “Connectivity.” Not shown is “Moore’s Law,” which Intel must continue to push to be competitive.

Intel’s new pillars, according to CEO Brian Krzanich. 5G modems are included in “Connectivity.” Not shown is “Moore’s Law,” which Intel must continue to push to be competitive.

4. Tick-tock goodbye.

For many years, Intel has set the benchmark for process technology and made damn sure Moore’s Law was followed. The company’s cadence of new architecture (Tock) followed by process shrink (Tick) predictably streamed products that found their way into PCs, laptops, the data center (now “cloud” and soon “fog”). But as Intel approached 22nm, it got harder and harder to keep up the pace as CMOS channel dimensions approached Angstroms (inter-atomic distances). The company has now officially retired Tick-Tock in favor of a three-step process of Architecture, Process, and Process tuning. This is in fact where the company is today as the Core series evolved from 4th-gen (Haswell) to 5th-gen (Broadwell—a sort-of interim step) to the recent 6th-gen (Skylake). Skylake is officially a “Tock,” but if you work backwards, it’s kind of a fine-tuned process improvement with new features such as really good graphics, although AnandTech and others lauded Broadwell’s graphics. The next product—Kaby Lake (just “leaked” last week, go figure)—looks to be another process tweak. Now-public specs point to even better graphics, if the data can be believed.

Intel is arguably the industry’s largest software developer, and second only to Google when it comes to Android. (Photo by author, IDF 2015.)

Intel is arguably the industry’s largest software developer, and second only to Google when it comes to Android. (Photo by author, IDF 2015.)

5. Embedded, MCUs, and Value-Add.

This last bullet is my prediction of how Intel is going to climb back out of the rut. Over the years the company mimicked AMD and nearly singularly focused on selling x86 CPUs and variants (though it worked tirelessly on software like PCIe, WiDi, Android, USB Type-C and much more). It jettisoned value-add MCUs like the then-popular 80196 16-bitter with A/D and 8751EPROM-based MCU—conceding all of these products to companies like Renesas (Hitachi), Microchip (PIC series), and Freescale (ARM and Power-based MCUs, originally for automotive). Yet Intel can combine scads of its technology—including modems, WiFi (think: Centrino), PCIe, and USB)—into intelligent peripherals for IoT end nodes. Moreover, the company’s software arsenal even beats IBM (I’ll wager) and Intel can apply the x86 code base and tool set to dozens of new products. Or, they could just buy Microchip or Renesas or Cypress.

It pains me to see Intel layoff people, retrench, and appear to fumble around. I actually do think it is shot-gunning things just a bit right now, and officially giving up on developing low-power products for smartphones. Yet they’ll need low power for IoT nodes, too, and I don’t know that Quark and Curie are going to cut it. Still: I have faith. BK is hell-fire-brimstone motivated, and the company is anything but stupid. Time to pick a few paths and stay the course.

CES Turns VPX Upside Down Using COM

Instead of putting I/O on a mezzanine, the processor is on the mezzanine and VPX is the I/O baseboard.

[ UPDATE: 19:00 hr 24 Apr 2015. Changed the interviewee's name to Wayne McGee, not Wayne Fisher. These gentlemen know each other, and Mr. McGee thankfully was polite about my misnomer. A thousand pardons! Also clarified that the ROCK-3x was previously announced. C. Ciufo ]

The computer-on-module (COM) approach puts the seldom-changing I/O on the base card and mounts the processor on a mezzanine board. The thinking is that processors change every few years (faster, more memory, from Intel to AMD to ARM, for example) but a system’s I/O remains stable for the life of the platform.

COM is common (no pun) in PICMG standards like COM Express, SGET standards like Q7 or SMARC, and PC/104 Consortium standards like PC/104 and EBX.

But to my knowledge, the COM concept has never been applied to VME or VPX. With these, the I/O is on the mezzanine “daughter board” while the CPU subsystem is on the base “mother board”.Pull quote

Until now.

Creative Electronic Solutions—CES—has plans to extend its product line into more 3U OpenVPX I/O carrier boards onto which are added “processor XMC” mezzanines. An example is the newer AVIO-2353 with VPX PCIe bus—meaning it plugs into a 3U VPX chassis and acts as a regular VPX I/O LRU.  By itself, it has MIL-STD-1553, ARINC-429, RS232/422/485, GPIO, and other avionics-grade goodies.

The CES ROCK-3210 VNX small form factor avionics chassis.

The CES ROCK-3210 VNX small form factor avionics chassis.

But there’s an XMC site for adding the processor, such as the company’s MFCC-8557 XMC board that uses a Freescale P3041 quad-core Power Architecture CPU. If you’re following this argument, the 3U VPX baseboard has all the I/O, while the XMC mezzanine holds the system CPU. This is a traditional COM stack, but it’s unusual to find it within the VME/VPX ecosystem.

“This is all part of CES’s focus on SWAP, high-rel, and safety-critical ground-up design,” said Wayne McGee, head of CES North America. The company is in the midst of rebranding itself and the shiny new website found at www.ces-swap.com makes their intentions known.

CES has been around since 1981 and serves high-rel platforms like the super-collider at CERN, the Predator UAV, and various Airbus airframes. The emphasis has been on mission- and safety-critical LRUs and systems “Designed for Safety” to achieve DAL-C under DO-178B/C and DO-254.

“We’ll be announcing three new products at AUVSI this year,” McGee told me, “and you can expect to see more COM-style VPX/XMC combinations with some of the latest processors.” Also to be announced will be extensions to the company’s complete VNX small form factor (SFF) chassis systems, such as a new version of the rugged open computer kit (ROCK-3x)—previously announced in February at Embedded World.

CES is new to me, and it’s great to see some different-from-the-pack innovation from an old-school company that clearly has new-school ideas. We’ll be watching closely for more ROCK and COM announcements, but still targeting small, deployable safety-certifiable systems.

The Secret World of USB Charging

There’s a whole set of USB charging specs you’ve probably never heard of because big-battery smartphones, tablets and 2:1’s demand shorter charge times.

Editor’s note: this particular blog posting is sponsored by Pericom Semiconductor.  

$5 chargers useNow that you can buy $5 USB chargers everywhere (mains- and cigarette lighter-powered), it’s tempting to think of them like LED flashlights: cheap commodity throw-aways. And you would’ve been right…until now.

My recent purchase of an Asus T100 Transformer Windows 8.1/Intel Atom 2:1 tablet hybrid forced me to dig into USB charging (Figure).

My own Asus T100 Transformer Book has a “unique” USB charging profile.  (Courtesy: Asus.)

My own Asus T100 Transformer Book has a “unique” USB charging profile.
(Courtesy: Asus.)

This device is fabulous with its convenient micro USB charging port with OTG support. No bulky wall wart to lug around. But it refuses to charge normally from any charger+cable except for the (too short) one that came with it.

My plethora of USB chargers, adapters, powered hubs and more will only trickle charge the T100 and take tens of hours. And it’s not just the device’s 2.0A current requirement, either. There’s something more going on.

Just Say “Charge it!”

The USB Innovators Forum (USB-IF) has a whole power delivery strategy with goals as shown below. Simply stated, USB is now flexible enough to provide the right amount of power to either end of the USB cable.

The USB Power Delivery goals solidify USB as the charger of choice for digital devices. (Courtesy: www.usb.org )

The USB Power Delivery goals solidify USB as the charger of choice for digital devices. (Courtesy: www.usb.org )

There’s even a USB Battery Charging (UBC) compliance specification called “BC1.2” to make sure devices follow the rules. Some of the new power profiles are shown below:

Table 1: USB Implementers Forum (USB-IF) Battery Charging specifications (from their 1.2 compliance plan document October 2011).

Table 1: USB Implementers Forum (USB-IF) Battery Charging specifications (from their 1.2 compliance plan document October 2011).

The reason for UBC is that newer devices like Apple’s iPad, Samsung’s Galaxy S5 and Galaxy Tab devices–and quite possibly my Asus T100 2:1–consume more current and sometimes have the ability to source power to the host device. UBC flexibly delivers the right amount of power and can avoid charger waste.

Communications protocols between the battery’s MCU and the charger’s MCU know how to properly charge a 3000mAh to 10,000mAh battery. Battery chemistry matters, too. As does watching out for heat and thermal runaway; some USB charger ICs take these factors into account.

Apple, ever the trend-setter (and master of bespoke specifications) created their own proprietary fast charging profiles called Apple 1A, 2A and now 2.4A. The Chinese telecom industry has created their own called YD/T1591-2009. Other suppliers of high-volume devices have or are working on bespoke charging profiles.

Fast, proper rate charging from Apple, Samsung and others is essential as harried consumers increasingly rely on mobile devices more than laptops. Refer to my complaint above RE: my Asus T100.

Who has time to wait overnight?!

USB Devices Available

Pericom Semiconductor, who is sponsoring this particular blog posting, has been an innovator in USB charging devices since 2007. With a growing assurance list of charge-compatible consumer products, the company has a broad portfolio of USB ICs.

Take the automotive-grade PI5USB8000Q, for instance. Designed for the digital car, this fast charger supports all of the USB-IF BC modes per BC1.2, Apple 1A and 2A, and the Chinese telecom standard. The IC powers down when there’s no load to save the car’s own battery, and can automatically detect the communication language to enable the proper charging profile (Figure). Pretty cool, eh?

The USB-IF’s CDP and SDP charging profiles require communication between the USB charger and the downstream port (PD) device being charged. Refer to Table 1 for details. (Courtesy: Pericom Semiconductor.)

The USB-IF’s CDP and SDP charging profiles require communication between the USB charger and the downstream port (PD) device being charged. Refer to Table 1 for details. (Courtesy: Pericom Semiconductor.)

As For My Asus 2:1?

Sadly, I can’t figure out how the T100 “talks” with its charger, or if there’s something special about its micro USB cable. So I’m stuck.

But if you’re designing a USB charger, a USB device, or just powering one, Pericom’s got you covered. That’s a secret to get all charged up about.

PCI Express Switch: the “Power Strip” of IC Design

Need more PCIe channels in your next board design? Add a PCIe switch for more fanout.

Editor’s notes:

1. Despite the fact that Pericom Semiconductor sponsors this particular blog post, your author learns that he actually knows very little about the complexities of PCIe.

2. Blog updated 3-27-14 to correct the link to Pericom P/N PI7C9X2G303EL.

Perhaps you’re like me; power cords everywhere. Anyone who has more than one mobile doodad—from smartphone to iPad to Kindle and beyond—is familiar with the ever-present power strip.

An actual power strip from under my desk. Scary...

An actual power strip from under my desk. Scary…

The power strip is a modern version of the age-old extension cord: it expands one wall socket into three, five or more.  Assuming there’s enough juice (AC amperage) to power it all, the power strip meets our growing hunger for more consumer devices (or rather: their chargers).

 

And so it is with IC design. PCI Express Gen 2 has become the most common interoperable, on-board way to add peripherals such as SATA ports, CODECs, GPUs, WiFi chipsets, USB hubs and even legacy peripherals like UARTs. The wall socket analogy applies here too: most new CPUs, SoCs, MCUs or system controllers lack sufficient PCI Express (PCIe) ports for all the peripheral devices designers need. Plus, as IC geometries shrink, system controllers also have lower drive capability per PCIe port and signals degrade rather quickly.

The solution to these host controller problems is a PCIe switch to increase fanout by adding two, three, or even eight additional PCIe ports with ample per-lane current sourcing capability.

Any Port in a Storm?

While our computers and laptops strangle everything in sight with USB cables, inside those same embedded boxes it’s PCIe as the routing mechanism of choice. Just about any standalone peripheral a system designer could want is available with a PCIe interface. Even esoteric peripherals—such as 4K complex FFT, range-finding, or OFDM algorithm IP blocks—usually come with a PCIe 2.0 interface.

Too bad then that modern device/host controllers are painfully short on PCIe ports. I did a little Googling and found that if you choose an Intel or AMD CPU, you’re in good shape. A 4th Gen Intel Core i7 with Intel 8 Series Chipset has six PCIe 2.0 ports spread across 12 lanes. Wow. Similarly, an AMD A10 APU has four PCIe (1x as x4, or 4x as x1). But these are desktop/laptop processors and they’re not so common in embedded.

AMD’s new G-Series SoC for embedded is an APU with a boatload of peripherals and it’s got only one PCIe Gen 2 port (x4). As for Intel’s new Bay Trail-based Atom processors running the latest red-hot laptop/tablet 2:1’s:  I couldn’t find an external PCIe port on the block diagram.

Similarly…Qualcomm Snapdragon 800? Nvidia Tegra 4 or even the new K1? Datasheets on these devices are closely held for customers only but I found Developer References that point to at best one PCIe port. ARM-based Freescale processors such as the i.MX6, popular in set-top boxes from Comcast and others have one lone PCIe 2.0 port (Figure 1).

What to do if a designer wants to add more PCIe-based stuff?

Figure 1: Freescale i.MX ARM-based CPU is loaded with peripheral I/O, yet has only one PCIe 2.0 port. (Courtesy: Freescale Semiconductor.)

Figure 1: Freescale i.MX ARM-based CPU is loaded with peripheral I/O, yet has only one PCIe 2.0 port. (Courtesy: Freescale Semiconductor.)

‘Mo Fanout

A PCIe switch solves the one-to-many dilemma. Add in a redriver at the Tx and Rx end, and signal integrity problems over long traces and connectors all but disappear. Switches from companies like Pericom come in many flavors, from simple lane switches that are essentially PCIe muxes, to packet switches with intelligent routing functions.

One simple example of a Pericom PCIe switch is the PI7C9X2G303EL. This PCIe 2.0 three port/three lane switch has one x1 Up and two x1 Down and would add two ports to the i.MX6 shown in Figure 1. This particular device, aimed at those low power consumer doodads I mentioned earlier, boasts some advanced power saving modes and consumes under 0.7W.

Hook Me Up

Upon researching this for Pericom, I was surprised to learn of all the nuances and variables to consider with PCIe switches. I won’t cover them here, other than mentioning some of the designer’s challenges: PCIe Gen 1 vs Gen 2, data packet routing, latency, CRC verification (for QoS), TLP layer inspection, auto re-send, and so on.

It seems that PCIe switches seem to come in all flavors, from the simplest “power strip”, to essentially an intelligent router-on-a-chip. And for maximum interoperability, of them need to be compliant to the PCI-SIG specs as verified by a plugfest.

So if you’re an embedded designer, the solution to your PCIe fanout problem is adding a PCI Express switch. 

USB Charging Becoming More Common than a 110V Socket?

USB is everywhere, and increasingly, it is the “socket” through which we charge all of our stuff. Microchip wants to be inside all those “sockets”.

[UPDATE: 8/13/13 11:45pm PDT. Changed from 12V to 12W; corrected sentence accordingly. C2]

The common 110VAC wall socket. (Courtesy: commons.wikimedia.org .)

The common 110VAC wall socket. (Courtesy: commons.wikimedia.org .)

I noticed that Home Depot now carries replacement 110VAC sockets with USB ports built in. What a handy way to avoid fumbling around for the elusive USB charger “wall wart”, especially since most non-Apple portable devices now sport micro USB charging ports and accept cheap $1 USB cables.

As USB proliferates to nearly every battery-operated consumer device, I’m wondering when the number of USB ports (2.0 and 3.0 SuperSpeed) will exceed the number of 110VAC wall sockets. The number of 110V sockets in the typical home is static (remodeling and extension cords notwithstanding), but the number of USB-charged digital cameras, Kindles, Samsung Galaxy IV smartphones, tablets, hubs and so on is increasing.

The common USB 2.0 connector. (Courtesy: commons.wikimedia.org .)

The common USB 2.0 connector. (Courtesy: commons.wikimedia.org .)

With this USB onslaught around us, it’s no wonder that more IC suppliers are focusing on USB silicon. And not just for USB 2.0 480 Mbits/s connectivity.

Case in point: Microchip’s latest USB port power controllers–the UCS1001-3 and -4, and the UCS1002-2. The new family not only supports active cables such as Apple’s irritatingly proprietary Lightning connector, but also 12W charging, enabling higher current up to 2.5A, plus priority charging capabilities.

 

Microchip aims to charge any USB device up to 12W. (Courtesy: Microchip .)

Microchip aims to charge any USB device up to 12W. (Courtesy: Microchip.)

A built-in sensor can report the amount of current being sourced so the port’s host system will know the difference between say, a Nexus 7 or an iPad (which require over 2A charging), and a digital camera battery or child’s toy. The family can also support future USB charging profiles, since USB is essentially becoming not only a 3.0 SuperSpeed connection channel (currently 5 Gbits/s), but an intelligent battery charger. Microchip is so bullish on USB, that they’ve even created two Eval Boards,

One of two eval boards, this one allows designers to explore programmable charging profiles. (Courtesy: Microchip.)

One of two eval boards, this one allows designers to explore programmable charging profiles. (Courtesy: Microchip.)

one of which emphasizes USB’s programmable charging capabilities.

If USB does become more ubiquitous than the common 110VAC wall socket, Microchip hopes they’ll be the equivalent of “Intel Inside” every USB host device. Yeah, I think it could happen.