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New Microcontroller is Web Enabled

Dallas Semiconductor Re-Engineers Its Microcontrollers For Network Computing

Dallas Semiconductor (now part of Analog Devices) have announced the introduction of microcontrollers that can directly serve up web pages. TINI™ (Tiny InterNet Interface) is a microcontroller-based development platform that executes code for embedded web servers. Remote devices can have preferences and settings adjusted from afar, just by having their administrator browse a web page hosted by the microcontroller-no other computers required.

The TINI development platform combines a powerful chipset and a Java™ runtime environment that exposes the extensive I/O capability of the Dallas microcontrollers. A Java programmer accesses the I/O from robust APIs (Application Program Interfaces) that include Ethernet, RS-232 serial, I2C, 1-Wire® net, CAN (Controller Area Network) and memory-mapped parallel bus. By using these APIs, programmers code functions without worrying about the underlying interface to hardware peripherals. The runtime environment is tightly coded for optimized network communications and efficient device I/O throughput.

“A device having a 115.2 kbps RS-232 serial input stream can continuously feed into a 10/100 Ethernet hub and still have idle CPU time for headroom,” says Clayton Ware, TINI product manager.

“We carefully coded the runtime environment to improve system performance and reduce the memory footprint. Our studies of Java-coded applications connected to real-world devices concluded that the most expensive part of the chipset was memory. We chose the high-speed Dallas microcontrollers over other architectures because we could code the runtime with substantially less memory. Our research indicated that a runtime environment with the customer-driven features and benefits of the TINI platform would require 53% or larger memory footprint if implemented on any other processor architecture.”

The full and complete runtime environment uses only 384 kbytes of Flash ROM and includes a full TCP/IP network protocol stack, a 25-kbyte JVM (Java Virtual Machine) and all of the a la carte APIs for device I/O. The APIs were coded in Java and reduced 65% using a class file optimizer. Furthermore, user application code can use the same space-saving technique to minimize memory usage. A compact memory footprint means more applications can meet the threshold of affordability and still benefit from the flexibility of the TINI runtime.

To give system developers a head start, the TINI Verification Module (DS-TINI-1) is built on a 31.8 x 102.9 x 9.5mm 72-pin SIMM using the TINI chipset. All of the chips are available as catalog items and can be purchased individually. A given application always includes the microcontroller but only uses the additional chips from the reference design to the extent needed. The DS-TINI-1 is based on the DS80C390 microcontroller and exposes the rich I/O capabilities provided by the platform. By using the DS-TINI-1 verification module, application software development can be performed simultaneously with hardware design.

The DS-TINI-1 is a proven and commercially available reference implementation for the TINI chipset. Its design details are published on the web and can be reused for specific implementations of the chipset. For embedded network devices where the SIMM form factor is desirable, the DS-TINI-1 is available to meet volume production requirements. TINI's microcontroller is capable of adding intelligence to many everyday devices that require small size, low power consumption, affordability and continuous uptime. This platform is standards-based both in its operating environment and in the support it gives to the underlying Internet technology, including protocols such as HTTP, TCP, UDP, IGMP and PPP. TINI developers write application software on top of the TINI platform to create network-based information systems. For many applications the coding can be all Java. For special situations the Java program can call on routines stored in native libraries. It is also possible to use a dedicated coprocessor like the DS87C520 microcontroller to handle time critical operations like continuously scanning a keyboard or driving a display.

TINI supports coprocessor connections with its serial and parallel APIs. The TINI I/O is kept open-ended using the 1-Wire net API to actuate switches and sense a distributed environment. The lighting control and door entry system sidebars are examples of extending TINI's microcontroller to the physical world using 1-Wire nets.

The path to the Internet can be wired or wireless. Steven Knudsen, Senior Vice President and CTO of PsiNaptic Communications said, “We saw the convergence of Java, Jini™ and low-cost wireless networking long ago. We wanted to give people a chance to put wireless Jini into the last place you'd want to have an IP address. When it came time to implement a cost-effective solution that met our requirements for size, power consumption and price range, TINI filled the bill. Merging TINI with Bluetooth™ has been a breeze, both on the hardware and on the software side.”

With the ability to support both wired and wireless networking, TINI is ideally situated for serving data from embedded devices. One of the first applications of the TINI platform has been to network legacy equipment that supports serial communications such as environmental sensors and controls. For example, a thermostat is a sensor/actuator with an often untapped potential for additional energy savings and enhanced comfort. Temperature setback is made more convenient using the computational resources of the network. For some customers, a Web-enabled thermostat would be the ultimate in convenience.

Said Clayton Ware, “There are innumerable devices designed for standalone operation that can be much more serviceable if they become part of a network. TINI has a dual role of a bridge to the Internet as well as local, off-line control.”

Dallas is completing the design of TINI's next generation microcontroller, the DS80C400. This microcontroller further reduces overall system cost by integrating the processor with the Ethernet network controller. The DS80C400 also increases system performance with its faster processing, lower power consumption and enhanced I/O capabilities.

According to Matt Adams, manager of Dallas Semiconductor's microcontroller design group, “With the development of the TINI platform, we are systematically reducing the chip count of the chipset for cost, size and power reduction.”

The DS80C400 will be shipping before year end with 10/100 Ethernet MAC and a 64 kbyte ROM containing a TCP/IP network stack supporting both IPv4 and IPv6. The chip also includes a CAN controller, three serial UARTs, a 1-Wire net controller, up to eight 8-bit bi-directional I/O ports with the ability to address up to 16 Mbytes external memory all for less than $15.00. As befits its acronym, TINI conquers the extreme size and cost limitations required to make the Internet viable for embedded system control.

The Analog Devices website address is www.analog.com.
[Reprinted with kind permission from Dallas Semiconductor]