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.

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.

Confused about all the different PC/104 and SUMIT-ISM specs? Then read this.

This is a short story of how ISA split apart the PC/104 industry. Here, all the hyperbole is distilled into a “Read this” primer that sorts out the various embedded board form factors.

I’ve written about the embedded boards industry for decades. At one point I even did some consulting for the PC/104 Consortium by recommending a focus on rugged and long-life applications and systems. But I can’t say I’m thoroughly familiar with all of the PC/104 specifications. There are just too darned many variations; who can keep them all straight?

Rest easy. Herein is a quick-and-dirty primer on all the specs, and how they compare. I’ve compiled this info courtesy of the PC/104 Consortium, the SFF-SIG, and friends from companies like WinSystems and Kontron.

PC/104 Consortium’s Specifications

I’m going to focus exclusively on PC/104-sized boards and ignore the related flavors like EPIC and EBX, but here’s how they look size-wise, compared to the original 90 x 96 mm (3.6 x 3.8 in) PC/104 board on the left:

A comparison of PC/104 board size to EPIC and EBX embedded boards.

A comparison of PC/104 board size to EPIC and EBX embedded boards.

PC/104 exclusively uses the ISA bus for stack-up and stack-down, whereas the other versions add or subtract PCI and PCI Express busses:

On a PC/104 board there are low-speed connections, all the way up to ISA, PCI, and PCI Express. This shows how the PC/104 Consortium's line up adds I/O and stacks.

On a PC/104 board there are low-speed connections, all the way up to ISA, PCI, and PCI Express. This shows how the PC/104 Consortium’s line up adds I/O and stacks.

In February 2013, the PC/104 Consortium ratified and made public the PC/104-Express and PCIe/104 versions shown on the right. PCIe/104 is their board-of-the-future and comes in Type 1 and Type 2 versions, depending upon the peripherals and feature set needed in the system. The brand new PCIe/104 has provisions to support PCI Express Gen 2 and Gen 3. The primary differences are shown in green. Type 2 would be used for the highest speed peripherals such as USB 3.0 or SATA; however, connector pin limitations forced PCIe x16 onto Type 1 instead of Type 2:

The new PCIe/104 comes in Type 1 and Type 2 versions, depending upon I/O requirements.

The new PCIe/104 comes in Type 1 and Type 2 versions, depending upon I/O requirements.

Note that the legacy ISA bus, and eventually the PCI bus (in PCIe/104) are dropped as the industry moves to PCI Express. These older ISA and PCI busses are supported by adding bridge cards to the middle of a PC104xxx stack as shown:

Adding ISA or PCI to the newer PC/104 stacks requires a bridge module in the sandwich.

Adding ISA or PCI to the newer PC/104 stacks requires a bridge module in the sandwich.

More information on stack-ups and how the PCI Express bus gets “lane shifted” as the stack grows can be found in the specifications for PCI/104-Express and PCIe/104.

Small-Form Factor SIG’s Specifications (SFF-SIG)

The industry fragmented over how to support the legacy ISA bus, and vendors that believed ISA I/O boards would remain popular for many years formed the SFF-SIG around 2008. Their PC/104-sized board is the same 90 x 96 mm (3.6 x 3.8 in) size but is called “Industry Standard Module” (ISM) to avoid copyright and trademark infringement issues. Instead, their specifications define Standard Unified Modular Interconnect Technology ISM boards (SUMIT-ISM) and the specification can be found here. An example of a larger EBX baseboard with SUMIT and PC/104 ISA connectors is shown below:

Caption: This is an EBX-sized baseboard that allows a SUMIT-ISM card to be stacked on it. The SUMIT-AB connectors are in the middle and the legacy PC/104 ISA bus connector is along the top edge. (Courtesy: WinSystems and TechBriefs.com .)

This is an EBX-sized baseboard that allows a SUMIT-ISM card to be stacked on it. The SUMIT-AB connectors are in the middle and the legacy PC/104 ISA bus connector is along the top edge. (Courtesy: WinSystems and TechBriefs.com .)

As for connectors and I/O on SUMIT-ISM boards, it uses the same Samtec Q2 double row, high speed 15.24 mm Q-strip connector system as does the PC/104 Consortium. The following table compares many of the common SUMIT-ISM I/O types (Column 1) to the PC/104 Consortium’s flavors, including the new Type 1 and Type 2 PCIe/104 just announced:

How PCI Express is implemented on SUMIT-ISM board and PCIe104 boards Type 1 and Type 2.

How PCI Express is implemented on SUMIT-ISM board and PCIe104 boards Type 1 and Type 2.

For additional explanation of how the ISA bus split the industry, read WinSystems’ article at TechBriefs.com .

Conclusions

It all comes down to a philosophical choice. If your design needs ISA and newer, contemporary processors, your choices are the original versions of PC/104 and SUMIT-ISM. When your system starts needing variations of PCI and PCI Express, you’ll need to examine how best to implement those busses in the stack-up: with or without bridge modules.  If you just want PCIe, then both SUMIT-ISM and the new PCIe/104 modules have you covered.

 

SMARC: ARM’d for a Power Play

ARM is migrating into the embedded board market, at the expense of x86 designs.

ARM is migrating into the embedded board market, at the expense of x86 designs.

In the world of multicore, it’s hard to get more cores than the quads now shipping in the latest smartphones, most of which are based upon ARM. But what about the board-level embedded market that I follow more closely?

You know it’s a foregone conclusion that ARM’s going to win the low power wars here too when even the x86 PC/104 vendors start musing about the need for ARM roadmaps.

 

WinSystems VP Bob Burckle spins a PC/104 board. The company is considering adding ARM processors to its predominantly x86-based boards.

WinSystems VP Bob Burckle spins a PC/104 board. The company is considering adding ARM processors to its predominantly x86-based boards.

In my discussion with WinSystems–a company that helps drive usually Intel-focused x86 trade consortia–Bob Burckle ponders an open standard form factor for ARM-based single board computers.  .

I’ve come to learn that ADLINK, Congatec, Kontron and others have pushed the very concept of ARM-based SBCs through the Standardization Group for Embedded Technologies (SGET) in a computer-on-module (COM) standard they’re calling Smart Mobility ARChitecture SMARC version 1.0.

Smart Mobility Architecture (SMARC) is a COM processor module ideally suited for ARM processors.

Smart Mobility Architecture (SMARC) is a COM processor module ideally suited for ARM processors. (Courtesy: Standardization Group for Embedded Technologies, SGET.org.)

It comes in 82mm x 50mm and 82mm x 80mm flavors, and Kontron is already implementing it for aircraft passenger In-Flight Entertainment systems.Figure 2 Kontron IFE plane cut-away

Look for ARM processors on PC/104, VME, COM Express…and SMARC boards soon. Choices will be from Texas Instruments, Atmel, Qualcomm, NVIDIA, Xilinx, and even AMD (which licensed the ARM for security engines in its APUs).

Kontron SMARC-sAT30 is a low profile platform based SMARC specification and integrates the 1.2 GHz NVIDIA Tegra 3 quad-core ARM processor (Cortex A9).

Kontron SMARC-sAT30 is a low profile platform based SMARC specification and integrates the 1.2 GHz NVIDIA Tegra 3 quad-core ARM processor (Cortex A9).

 

“Blah, blah, blah. Just do something.”

Executive Tech Interview:

As we finished our telephone interview acquainting me to rugged systems supplier PCI-Systems, I asked company president Claus Gross what best summed up his mission statement. You know, the old “elevator” pitch one-liner. He paused on the long-distance Skype call from Israel where it was nearly 10pm, and replied: “We’re changing common thinking.”

Claus Gross, president and head engineer of PCI-Systems.

Claus Gross, president and head engineer of PCI-Systems.

Then he a paused and added: ”Rugged systems to the bone. As in the George Thorogood song.” Guess The Destroyers were popular in Germany; who knew?

This cleanly sums up the man’s personality as his company, which was founded in 1995 conducting stress corrosion cracking tests on pipelines, constantly tries to push the state of the art in embedded systems engineering. From automated corrosion test systems PCI-Systems moved into data acquisition, then into standards-based small form factors (SFFs) to become the sixth (6th) original member of the PC/104 Consortium. Their love affair with PC/104 ended soon thereafter as Claus discovered customers couldn’t deal with the dangling cables and I/O challenges of stackable ISA-based boards.

Thus began his epic quest for better open standards.

Claus next turned to PICMG’s CompactPCI and soon discovered a niche in conduction-cooled boards. At the time 6U VME was the de facto rugged conduction-cooled board type, but companies like PCI-Systems and then-SBS (later acquired by GE) found ways of ruggedizing the tidy, small 3U cPCI boards. These efforts lead Claus to design chassis for their boards and also discover better ways of cooling them. Along the way, PCI-Systems discovered that the real value they brought to the market wasn’t another PC/104, CompactPCI, or even VPX single-board computer (SBC), it was in the systems design. And in particular, the chassis.

My first interaction with Claus was probably in 2011 when he unveiled his microATR chassis concept to the VITA Standards Organization (VSO), a proposal that would later become VITA 73. (Refer to the article “The smaller VITA 73 Small Form Factor“.)  Brash and self-confident, Claus entertained, brow-beat, wowed and irritated the group of about 50 VSO members as he described his vision for turning a 2.5-inch SSD form factor into a set of conduction-cooled cards with more useable density than VITA’s own 3U VPX. Clearly Claus has no patience for what he implied was “dumb” engineering. Still hates it.

Example of a PCI-Systems VITA 73 rugged enclosure with 2.5-inch inspired modules.

Example of a PCI-Systems VITA 73 rugged enclosure with 2.5-inch inspired modules.

Today, the self-funded family company (the author of our article mentioned above is Ben Gross) employs about 25 people, with some design and operations in Sunnyvale, California, manufacturing near Frankfurt, Germany, and the core of design near Kiev in the Ukraine. PCI-Systems is impressive because the company focuses on what it does best–hardcore (dare I say “bbad to the bbone?”) mechanical and signals engineering–while sticking other company’s boards into their slots when there’s no value-add for PCI-Systems.

Q7 SBCs from Congatec are a favorite, freeing Claus to focus on uniqueness such as the patent-pending “3D stacking fabric backplanes”, special wedgelocks, a new VPX connector to replace the allegedly vibration-prone MultiGigRT2 wafer connector (Claus says they’re working with defense prime DRS), and soon a mechanical design for safe lithium-ion batteries.

NTSB photo of burned battery from a JAL-owned Boeing 787 Dreamliner.

NTSB photo of burned battery from a JAL-owned Boeing 787 Dreamliner.

As PCI-Systems starts to rack up mechanical and systems design wins, Claus isn’t toning down the rhetoric when he sees “dumb designs”. As our interview time waned, he railed on about how he’s flying over 100,000 miles per year for business “with my butt over Boeing lithium-ion batteries“, implying he’s as concerned as the rest of the world with the volatility of battery chemistry.

But unlike most frequent fliers, Claus is set to do something about it. PCI-Systems is destined to soon propose new versions of VITA 62 (power supply standard) and VITA 77.x (VPXi chassis) designed to safely cool and electrically isolate lithium-ion batteries. His message: the batteries should be broken down into smaller cells that can be conductively cooled and managed best for safety.

Dawn Figure 3

Example of a VITA 62 rugged power supply. (Courtesy of Dawn VME.)

He’s promised to share with us his latest mechanical design as soon as it’s ready. And I’m sure he won’t be bashful about why his battery standard is the best one. So far his track record is pretty darned good.