Add graphics to embedded-system applications

by Graham Prophet

Much recent work in operating systems has focused on producing more compact versions of graphical-user-interface (GUI)-based systems, such as Windows CE. In contrast, Wind River has been looking at the reverse: adding graphics to already-compact operating systems. Increasingly, users will expect embedded operating systems to have sophisticated GUIs. And, as opposed to the desktop market, in which users expect a standardised look and feel, embedded-system users place more emphasis on the ability to create a customised appearance.

With four software modules, Wind River lets you create interfaces that are customisable, scalable, compact, and standards-compliant and that have Internet connectivity if the application requires. For C++ code, Wind River has acquired Zinc Software and has produced Zinc for VxWorks. For interfaces in HTML, Wind River wrote eNavigator and HTMLWorks, and, for those working in Java, Wind River offers the PersonalJava graphics module. Each module communicates with VxWorks via the UGL2D common graphics library, which Wind River hopes to make a standard.

PersonalJava has a scalable implementation of Java's AWT graphics interface, optimised for resource-constrained applications, providing an interface between AWT components, such as menus and buttons, and primitive graphics elements. Windowing is optional. HTMLWorks (Picture), a set of HTML and Javascript components, allows you to build complex interactive GUIs for network-connected devices that don't need full Web browsing. "Directed browsing" provides full Web-connected applications, such as information kiosks. For this browsing, you use eNavigator, a package with HTML parsing and layout engine as well as Javascript support.

You use the Zinc tool set to build small-footprint GUIs that are native-compiled for higher perform-ance embedded systems, using a C++ application-programming interface. Zinc includes a set of GUI libraries, a visual design tool, and a portable make utility. The libraries give you ready-made windows, buttons, notebooks, and tables, and you can customise the GUI objects to give a distinctive appearance and feel to the final product. Zinc is also available for other RTOSs.

Wind River Systems, Birmingham, UK. +44 121 628 1888, www.wrs.com. Circle No. 547

Low-power DSPs serve infrastructure and terminal applications

Two DSP chips from Texas Instruments extend the fixed-point TMS320C54 family in different directions. The C5402, a low-cost processor, targets terminal equipment or PDAs.

TI packages the higher performance chip in a mBGA chip-scale package; in the 12X12-mm outline, the chip contains a dual-processing core with six serial ports, a DMA controller, and a 16-bit host-port interface. It consumes 120 mW at 200 MIPS. The C5402 provides a 100-MIPS core with 16k words of RAM, 4k words of ROM, and a range of peripherals; it consumes 58 mW of power. Prices are $55 and $5 (50,000), respectively. By using compatible processor architectures at the infrastructure and user-terminal ends of the telecomm loop, you can realize savings by reusing software. Code-development tools are compatible with the new processors, and 30-day-free evaluation copies of code generation and simulation tools are available for downloading from www.ti.com/sc/docs/dsps/products/c5000/c54x/index.htm. TI's RTDX aids system analysis. It uses JTAG access to the chip to give a continuous and real-time view of the running software.—by Graham Prophet

Texas Instruments, Nice, France. +44 1604 663399, www.ti.com/sc. Circle No. 548

Quad-DSP boards speed data routing with crossbar switches

A crossbar switching architecture to speed data flow between multiple processors is at the heart of a range of VME boards from Blue Wave Systems, targeting the defence and telecommunications markets. The company based the boards on TI (www.ti.com) C6000 DSPs. The dynamically reconfigurable crossbar switch provides as many as four concurrent links, each running at 264 Mbytes/sec between the DSPs. The highest performance VME/6450 board runs at 4 Gflops, or 6400 MIPS, for computationally intensive, array-processing tasks, such as radar and sonar. Two other boards target wireless and wired systems. C6240 is intended for digital radio and software-radio applications in both military and commercial cellular systems. You can load the device with four C6201 or 6701 processors, and it has two PCI-mezzanine-card (PMC) sites. The fixed-point processors are aimed at standard radio systems; the floating-point CPUs, smart-antenna or phased-array systems with large-dynamic-range requirements. Another quad-processor board, the C6400, targets wired applications, such as echo cancellation, voice over Internet Protocol, and speech recognition. The device provides the same choice of fixed- or floating-point processors, along with a speech-bus interface, and MPC860 PowerQuicc system controller and a PMC site; expansion boards connect standard telecomm interfaces.—by Graham Prophet

Blue Wave Systems, Loughborough, UK. +44 1509 634300, www.bluews.com. Circle No. 549

Op-amp design cuts drift over time and cuts out 1/f noise

The LMC2001 op amp from National Semiconductor provides precision performance over an extended service period, reducing or removing the need for adjustment or calibration service. The device offers input offset better than 40 µV with a drift greater than 5 µV over 10 years. The amplifier also continuously auto-corrects over its temperature range. The 6-MHz (gain-bandwidth product), single-supply (5V) device swings to within 30 mV of either rail on its outputs. It offers a 1% settling time of less than 250 nsec and a slew rate greater than 5V/µsec. You can use it in instrumentation amplifiers, thermocouple amplifiers, strain-gauge bridge amplifiers, and any other applications requiring long-term stability. Price for the 3X3-mm, SOT23-5-packaged device is $1.20 (1000).

National uses a new topology that involves a 6-MHz amplifier in parallel with a chopper-style amplifier (but not a conventional chopper-stabilised amplifier) that forward-corrects the errors. The switching process yields a 10-kHz noise component, but spread-spectrum techniques spread the noise energy. National claims that the device eliminates 1/f noise, so you can measure to low signal frequencies and still not lose accuracy to an increasing noise floor. Also, the design is immune to the adverse effects that switched capacitors on the front ends of ADCs have on the output stages of conventional chopper-stabilised amplifiers. National plans to add dual packages, lower operating voltages for true rail-to-rail inputs and ground-rail current sensing, and further noise reductions.—by Graham Prophet

National Semiconductor, Furstenfeldbruck, Germany. +49 180 532 78 32, www.national.com. Circle No. 550

Fast 8-bit microcontroller runs "virtual peripherals" in software

Scenix Semiconductor's 8-bit SX18/28BC microcontroller provides a new option for executing DSP and other parallel-processing tasks that might otherwise require a medium-performance DSP or one or more programmable-logic ICs. The 100-MHz chip provides one instruction per clock cycle and executes complex functions as software modules, or "virtual peripherals." The single-cycle execution provides a deterministic response so that the chip services all interrupts in 30 nsec, enabling signal processing without introducing jitter. The device lets you perform gen- eral-purpose embedded-control algorithms and task-specific functions on one processor.

You can also execute functions such as digital filtering as software-callable modules. Scenix asserts that a fourth-order, finite-duration FIR takes less than under 10 µsec. For applications that require a range of functions, you can use less silicon area than implementing the same functions on programmable logic, in which all functions would reside on the PLDs. The SX series uses a RISC-like instruction set with a four-stage pipeline for throughput, fast on-chip flash/ EEPROM program memory, and a fast SRAM register file, allowing functions to be called and run in software in a comparable time with equivalent hardware.

A new module for the µCs, a 1200-bps FSK/2400-bps differential-PSK V.22 modem includes dual-tone multiple-frequency and caller-ID features and targets embedded communications in remote-data-gathering and point-of-sale applications. Scenix makes many virtual-peripheral functions available for downloading from its Web site. A range of third-party development, compiler, and programming tools is available.—by Graham Prophet

Scenix Semiconductor, Santa Clara, CA. +1 408 327 8888 www.scenix.com. Circle No. 551

Module design cuts the cost of embedding the PC architecture

If you want to use the x86 or PC architecture as a "drop-in" computing solution for an embedded application, you can find numerous software products that keep the size of the embedded code manageable and that optimise the result for the embedded world. According to German manufacturer Jumptec, the same is not true of hardware from the PC world, with most offerings being either PC motherboards or the same functions implemented on a smaller, usually rack-mounted, format. An exception is the PC/104 format, but Jumptec says that this format's interconnections, which it inherited from the regular PC format, hampers PC/104's achievable cost. To overcome those limitations, Jumptec has defined the DIMM-PC, a 68X40-mm card that uses the mass-produced 144-pin connector intended for DIMMs as its only I/O path, cutting OEM costs by approximately $60.

The DIMM-PC is a complete PC, currently available as a 33-MHz 386SX CPU with 1, 2, or 4 Mbytes of RAM and 1 to 8 Mbytes of BIOS- or IDE-compatible flash disk and operates from a 5V supply. The company plans to add more powerful versions based on a later x86 family. Jumptec says the card fits between PC/104 and a custom device in volume/cost calculations. A PC/104 solution offers the lowest cost for a few units because you can connect it with standard cabling and without special hardware. The DIMM-format unit requires some initial investment in a board design to carry the DIMM connector, but, once that is complete, the per-unit costs are lower, and prices for the modules start at $25 in volume. A starter kit mounts the module on a PC/104-format board with the standard cabling to connect it to the outside world.—by Graham Prophet

Jumptec, via Diamond Point, Rochester, UK. +44 1634 722390, www.jumptec.de. Circle No. 552 

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