While the bulk of the $9.7B U.S. sensors market is MEMS-based accelerometers—the not-so-secret sauce empowering the 34 million Wii game consoles sold to date—there were plenty of other sensor technologies on display, including proximity, light, piezo-electric, thermal, pressure, touch, gas, chemical, IR and probably more that I missed. The applications consisted of a wide range of consumer, industrial, medical, environmental and security devices, all of which relied on sensor data for input. If you can’t measure it, you can’t control it—the problem this show addressed.

On with the Show

Instead of rolling out individual products ROHM Semiconductor chose to showcase a number of them at once with its Sensor Race Track, which featured a model Hummer circuiting a track populated with nine different sensors:  3-axis accelerometers, an ambient light sensor, a UV sensor, a Hall Effect sensor, an optical proximity sensor and an inclinometer. All of these inputs fed into a sensor hub and then to a wireless networking module, which in turn presented the data in real time on a large screen.

Digi International used Google Earth to demonstrate its “cloud-based wireless sensor network,” which enables centralized monitoring and control of disparate resources worldwide—from rotating solar panels to tracking trucks to monitoring vending machines—all using wireless sensors nodes connected to the internet.

Some companies such as ROHM, Epson, MEDER and many others displayed numerous individual sensors; others showed products that could integrate data from different sensors—so called sensor fusion. STMicro highlighted its iNEMO inertial measurement unit (IMU) devices, which combine data from various motion sensors with magnetic (compass), barometric/altitude and GPS data to enable location-based services. ST stressed the low-power angle, a theme echoed by TI, Maxim, Microchip, Linear Tech, Analog Devices and most other vendors. The chip companies, by and large, focused on managing the power going to and the data coming from remote sensor devices.

Energy Harvesting

A number of companies focused on extending the useful life of remote sensor nodes by using energy scavenging techniques. Cymbet uses a combination of tiny solar panels backed up by their proprietary thin-film batteries to supplement coin cells in wireless sensor nodes; Microchip and TI, among others, rely on Cymbet’s board to power their energy scavenging kits.

Powercast pulses RF from a central source to top up power in and gather data from remote sensor nodes. The Powercast P2110 receiver is an RF energy harvesting device that converts RF to DC and stores it in a capacitor. The Powercast transmitter can power an array of battery-free receivers throughout a building for industrial monitoring, HVAC and smart-grid applications—all of which resembles a wide-area active RFID system.

Nextreme’s miniature, embedded thermoelectric generators (eTEG) are essentially thin-film thermocouples that fit between a heat source (MCU, PA, etc.) and its heatsink. Converting temperature differences of as little as 5°C into electrical power, the eTEG is designed for powering gas sensors; trickle charging wireless sensors in dark or remote places; and improving fuel efficiency in automobiles.

Ever since Intel hit the Power Wall in 2004—when the Pentium 4 drew 150W and approached 1000 pins—low-power design has come into its own. Over the past decade smart engineers have come up with a seemingly endless number of innovative tricks to stave off the frequently predicted death of Moore’s law, which was supposed to happen first at 90 nm, then 65 nm than 40 nm, etc. Still, when gate doping variations of several atoms can cause a transistor to fail, the laws of physics are finally asserting themselves. As one wit observed recently about Moore’s law, the party isn’t over but the police have arrived and the volume has been turned way down.

On one level better process technologies have gone a long way toward enabling low-power design. Smaller geometries enable lower voltage cores, which helps exponentially on the power front. Strained silicon, silicon-on-insulator, high-K metal gates and other clever process innovations have all enabled the continuing push to smaller geometries and more energy efficient designs.

On the system level design engineers have developed a long succession of power management techniques. Modern MCU’s typically rely on power gating, clock gating, and more recently dynamic (even adaptive) voltage and frequency scaling to minimize power consumption in both active and inactive modes. With the number of sleep modes and voltage islands proliferating, fine-grained power management becomes so complex that most CPUs now rely on separate power management ICs (PMICs). Since MCU’s are more self-contained, much of the power management burden is shifted from the embedded developer back to the chip designer.

Low Power –> Ultra-Low Power

If not the chips then the ‘race to the bottom’—in terms of power—between MCU vendors is getting heated. With the numbers they’re hitting, it’s hard to argue that the newest MCUs are indeed ‘ultra-low power’.

TI promotes its 16-bit RISC ‘ultra-low power’ MSP430 line in a wide range of applications, including a wireless sensor circuit that can operate from a single coin cell for up to five years (thanks in part to a very short duty cycle). The MSP430C1101—with 1kB of ROM, 128B RAM, and an analog comparator—draws 160 µA at 1 MHz/2.2V in active mode, 0.7 µA in standby mode, and 0.1 µA in off mode. This week TI announced its Grace software platform, a free plug-in for Code Composer Studio that provides a detailed graphical user interface to simplify low-level programming of MSP430 MCUs.

Microchip’s answer to the MSP430 is its eXtreme Low Power PIC Microcontrollers with XLP Technology.  XLP processors include 16 to 40 MIPS PIC24 MCU & dsPIC DSC families with up to 256 KM of memory and a variety of I/O options. On its web site Microchip emphasizes how low power its devices are in deep sleep mode, comparing the PIC24F16KA102 favorably to the MSP430F2252 LPM3 at 3V. Comparing power in active modes is considerably more complex, being highly application dependent. That’s what evaluation kits are for.

Silicon Labs claims that its C8051F9xx ultra-low-power product family includes “the most power-efficient MCUs in the industry,” with both the lowest active and sleep mode power consumption (160 µA/MHz /50 nA for the C8051F90x-91x) compared to “competitive devices.” Comparing data sheets is often and exercise in “apples and oranges,” but the numbers do justify the impression that ‘ultra-low power’ is a lot more than marketing hype.

NXP is definitely into green MCUs with its GreenChip ICs that “improve energy efficiency and reduce carbon emissions.” NXP’s recently announced LPC11U00—being a Cortex-M0-based MCU—is decidedly low power, but this one focuses more on connectivity, incorporating a USB 2.0 controller, two synchronous serial port (SSP) interfaces, I²C, a USART, smart card interface3 and up to 40 GPIO pins.

STMicroelectronics features 8- and 32-bit families of ultra-low-power MCUs, apparently skipping over the 16-bit migration path that Microchip needed to fill. The 8-bit STM8L15xx CISC devices can run up to 16 MIPS at 16 MHz but still only draw 200 µA/MHz in active mode and 5.9 µA down to 400 nA in various sleep modes. Like NXP, ST is into connectivity, including a wide range of options on different devices.

Connectivity and flexibility are the main selling point for Cypress’ programmable system-on-chip or PSoC. PSoC 5 is based on a 32-bit Cortex-M3 core running up to 80 MHz. Incorporating a programmable, PLD-based logic fabric, the CY8C54 PSoC family can handle dozens of different data acquisition channels and analog inputs on every GPIO pin. The chip draws 2 mA in active mode at 6 MHz, 2 µA in sleep mode (with RTC) and 330 nA in hibernate with RAM retention.

Grill the Gurus

If after reading all the datasheets you still have questions, this Thursday you can ‘grill the gurus’ online in real time as EE times presents the Digi-Key Microcontroller Virtual Conference: New Directions in MCU Designs, from 11-6 EDT. From 11:15-12:15 EDT I’ll be moderating the panel “Low-Power Design—Keeping Hot Designs Cool,” and questions from the audience are encouraged.

From 12:30-1:30 EDT Scott Roller, Vice President and General Manager, Microcontrollers at Texas Instruments will deliver the keynote, “What Will Make The Biggest Impact: Low Power? Connectivity? Simplicity? Yes.” TI sees the market for embedded MCUs exploding over the next several years, and it’s working on some interesting innovations that should open up new markets for developers.

Throughout the day there will be series of panels, webcasts, chats and exhibits at (virtual) pavilions of interest to the embedded design community. Click here to check it out. I hope to see you there.

Cadence

In anticipation of this show Cadence is “working on a press release with various companies including ARM on the topic of SOI.” They won’t tell us anything more right now, so “stay tuned for more exciting developments.” The SoIC Consortium is also appearing on my panel on New Frontiers for ARM Cores and doing a separate webcast with Cadence on SoI (Want to know how to save power and improve chip performance? Get ready for SOI). Hmm, this will be interesting.

NXP

Recently NXP introduced the ARMPNX847x/8x/9x, the world’s first fully integrated 45nm Set-Top Box SoC platform incorporating multi-channel broadcast receivers. The NXP PNX847x/8x/9x utilizes the ARM Cortex-A9 MPCore and  ARM Cortex-M3 processors to enable a high performance, energy-efficient solution in a low-cost form factor. NXP should have considerably more to say on the subject at this conference.

CoWare

CoWare is expected to announce support for “the latest ARM Cortex processors,” details to follow. ARM certainly sees the value of CoWare’s electronic system virtualization (ESV) tools as evidenced by their recent announcement of a partnership with CoWare to provide system designers with a new SystemC solution for the efficient configuration of AMBA NIC-301 Network Interconnect based SoC Designs. I wouldn’t be surprised to hear of further CoWare support for ARM-based designs.

Isilon

ARM has recently deployed Isilon Systems’ scale-out NAS with solid-state drives to reduce replication of millions of files from 17 hours to two hours. Isilon will explain how its IQ 10000X-SSD in combination with its asynchronous data replication software SyncIQ can speed up and safeguard mission critical applications such as microprocessor design.

Sonics

Sonics is producing a webcast for the show titled Cracking the Multi-Layer Design Code: How to Cost-Effectively Simplify and Optimize AMBA-Based Designs. They haven’t told us yet what they’ll be announcing at the show, but any engineer designing multi-layer AHB bus structures should definitely check this out. Expect to hear details about how their on-chip communications solutions will support phase one of ARM’s new AMBA 4 protocol.

OK, the following sponsors haven’t told us yet what they intend to announce, so we’ll make some educated guesses:

Cypress

Not too long ago Cypress saw the wisdom of migrating from an 8051-variant MCU architecture for its popular PSoC MCUs to an ARM-based design. Cypress’ focus on programmable peripherals and interconnects are a topic that should be of interest to the rest of the ARM development community. What they have up their sleeves remains to be seen—perhaps at this month’s conference.

Synopsys

Synopsys has long been involved with ARM-based designs, from system-level design down to implementation and sign-off. They’ve also done some recent acquisitions—such as CoWare—that underscore their targeting of processor-based designs. With Cadence also on the program, you can be sure that Synopsys will have something attention-grabbing to say. OK, I have no idea what.

ARM

ARM hasn’t signaled that it intends to make any major announcements at the conference, but their CTO Mike Muller—who is giving the keynote—has plenty to say. I’ll spill the beans about that in next week’s blog post.

–John Donovan