NUREMBERG, Germany – Freescale Semiconductor is preparing for what it thinks will be the next driver of microcontroller sales, the Internet of Things (IoT), with the introduction of a 32-bit microcontroller measuring just 1.9-mm by 2.0-mm. That's the not the die size but the complete Kinetis KL02 MCU--in its chip-scale packaging.
The company is working to support such small MCUs with a local, ultra-low-power radio unit that will start as a stand-alone device but which could be integrated system-in-package or even monolithically.
Speaking at the Embedded World exhibition, Geoff Lees, senior vice president at Freescale responsible for i.MX and Kinetis microcontrollers, said that the company would be "aiming products at consumer and industrial applications and trying to reach a much broader customer base." He added: "We see the internet of things as the next big driver of microcontrollers."
The KL02 contains a 48-MHz ARM Cortex-M0+ core with 1.7 to 3.6 volt operation. There is 32-kbytes of on-chip flash memory and 4kbytes of SRAM together with a 12-bit analog-to-digital converter. Freescale claims the KL02 is 25 percent smaller than the next smallest ARM microcontroller and holds great potential for small form factor applications such as consumer devices, remote sensing nodes, wearable devices and ingestible healthcare sensing. At the same time space-constrained applications that previously couldn't include an MCU can now be upgraded.
The KL02 is a wafer-level chip-scale package wherein the die is connected directly to the solder ball interconnects and, in turn, to the printed circuit board (PCB). This removes the need for bond wires or interposer connections, which minimizes die-to-PCB inductance and improves thermal conduction and package durability for physically harsh environments. The KL02 device is the third CSP MCU in the Kinetis portfolio, and CSP MCUs with increased performance, memory and feature options are planned throughout 2013.
"A lot of our business will be based on chip-scale packaging and we can also put multiple chips, passives and discrete in chip-scale packaging," said Lees.
When asked if Freescale would be embedding an RF transceiver in chip-scale packaging Lees said Freescale is working on a multi-mode radio in a 90-nm manufacturing process. Designed to operate on a 2.4-GHz carrier it would cover Bluetooth and ZigBee standards but not Wi-Fi IEEE802.11. Lees argued that such a broadband radio does not really address the same IoT applications Bluetooth and ZigBee.
Lees said he expected Freescale to be sampling the mixed-mode RF by mid-2013 and an integrated multi-die component including MCU and RF before the end of 2013.
Why 32 over 16 or 8 bit? Many reasons...
First of all, ARM 32 bit cores scale well from small M-class up to high performance A-class - one can re-use applications written for M on higher performance cores when more performance is needed (i.e. moving from sensors more into the cloud for IOT). Another reason is that memory is costly and it "usually" requires fewer 32 bit instructions to accomplish a given task than if one used 8 or 16 bit instructions (ARM's M0/M0+, by the way uses the thumb (16 bit) instruction set)) thus requiring less memory for code storage. Performance is also typically improved using 32 bit devices (larger registers, greater addressing range). More power may be consumed switching 32 bit registers and supporting a 32bit pipe-line but, again, as fewer instructions may be executed compared to 8/16 bit, one is using more energy but over shorter time.
There's ongoing discussion what wireless architecture will be "the one" for (hopefully) uprising IoT market. Low-power WiFi, Bluetooth LE, 802.15.4 Zigbee are leading the market, but there's also more than a dozen of so-called "optimized for IoT" architectures (ANT+, Z-Wave, EnOcean, MyraNet, DASH7, WirelessHART... you name it). Many uses 2.4GHz but some uses sub-GHz band.
Freescale offers two types of "Kinetis W" series radio-integrated MCUs, KW01 with proprietary sub-GHz radio and KW20 with 2.4GHz 802.15.4. As long as I know, there's no Freescale Bluetooth (LE) chip has been released yet. It is interesting to see how they can do well with "multi-mode radio" chip, and how do they marketing discrete radio chip versus KW series radio-integrated SoCs.
@daleste, your question might have a very simple response that is not about complex architectural analysis on 8/16/32 bits. Per ARM's own claim, the M0 core is 32-bit and is the smallest ARM core available. ARM jumped a bit over developing 16-bit cores.
Rick, you are hitting on one of the hurdles M2M faces in the existing (brown field) and new (green field) markets. Industrial automation (SCADA, CAN) have many applications but penetration there has been a tough sell for wireless M2M nodes. Legacy implementations from the likes of GE, Rockwell, are not going to be displaced any time soon. Naturally some of the attention has been turned toward medical monitoring where many new startups have sprung lately in the Silicon Valley (I think I introduced one of them to you at DesignCon 2013).
I hope 2013 is the year a better picture emerges for IoT. There is a lot that is needed in software solutions like analytics and prognostics.
The issue of power consumption is a tricky one and it depends on what one employs as a system, whether using the one above or others like i.MX283 also from Freescale. If the IoT is deployed / configured using ZigBee, the battery life is in years; in days for Bluetooth and in hours for WiFi!
Typical WiFi 802.11/a/b/g/n versions will restrict to nodes in IoT within a 30m reach node-to-node; one can always have router nodes in the mesh and extend its reach but it is impractical for outdoor & low data applications (like weather / infrastructure health monitoring).
For ZigBee, Freescale has MC1322x SoC which I believe consumes sub mW power in sleep mode /quiescent state.
In India IoT market is currently growing well and most of the chipsets we use here are either from TI or from chinese vendors .... Freescale does not have potential network in India and their support quality is also very low .... It's very doubtful if this chpset will get considerable amount of Indian market .....
The hard thing about IoT, one Berkeley researcher told me recently, is that many of the systems address Luddite markets where they are replacing mechanical or no systems at all--a hard sell, and a more fragmented market than even the so-called catch-all embedded sector.
This will take time and hard work.
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