Colorado Springs, Colo. -- Freescale Semiconductor Inc. will port the core ZigBee protocol stack to the ColdFire control architecture as gateway applications in home automation and industrial control move to 32-bit control planes.
In the first applications, a two-chip solution will combine ColdFire, using medium-access control software, with a dedicated transceiver for the RF network. Later, system-on-chip applications will combine ColdFire cores with communications cores as well as peripheral and I/O modules.
As additional full ZigBee adjuncts to the base IEEE 802.15.4 protocols are released for Motorola's 8-bit controller lines, those will be added to the ColdFire suite as well. The ColdFire MCF5282, MCF5213 and MC5223x families are included in the current port.
Meanwhile, the current protocol stack software, based on technology from Figure 8 Software Inc., will be replaced with stacks developed at Freescale and called the BeeKit. Chipcon Group ASA of Oslo, Norway, acquired Figure 8 in January 2005, and Chipcon in turn was acquired by Texas Instruments Inc. in December for $200 million.
Freescale is satisfied with its software pact with TI, said Brett Black, commercial wireless operations manager at Freescale. The Figure 8 stacks will continue to be supported for legacy products, Black said. But new ZigBee designs in both the 8-bit and 32-bit control domains will use the BeeKit, giving Freescale more control over its destiny.
Delayed completion of the full ZigBee standard caused some OEMs to implement a standard 802.15.4 stack for their first-generation products, Black said, but the tide is turning. A year ago, fewer than 5 percent of customers used what would be considered a full ZigBee protocol stack, while 40 percent used 802.15.4 and more than 50 percent used an even more basic "Simple MAC" structure for industrial wireless control. Now, Black said, 20 percent of new customers are using the full ZigBee stack, 40 percent are using 802.15.4 and 40 percent are using the simple MAC.
"Some will continue to want the IEEE-only software; some cost-constrained customers may even stick with the original Simple MAC. But we expect greater percentages to keep turning to ZigBee," he said.
A variety of fleet management, agricultural and transportation markets will turn to ZigBee networks after initially considering simpler RFID or near-field communications, Black predicted, in part because bringing a tag close to a reader is not always practical. He cited ZigBeef, a company providing ZigBee as an alternative to close-range RFID tagging of cattle. The latter has not been successful, because "cows have their personal-space concerns, and the near-contact systems violate that," Black said.
Devices like the MC1321x might provide a blueprint for ColdFire system-on-chip integration. That part integrates a "ZigBee ready" transceiver with an HSC 08 controller and a transmit-receive switch, then adds peripherals like flash memory, pulse-width modulation control and A/D conversion. For higher-performance home automation gateways, a ColdFire-based SoC could add Ethernet MAC or USB support.
The BeeKit is more than an alternative protocol stack to Figure 8, Black said. It is a full development environment, including a linker; debugger; graphic interface, for application development; and source-code input files, to develop applications from templates. The software suite, being introduced in Shanghai this week, will be shown at the Chicago Sensors Expo in June and at Freescale's own developers conference a month later.