November 6, 1997

WHAT'S HOT IN THE DESIGN COMMUNITY

Point-to-point ring turbocharges PCI bus

You may think that the PCI-bus specification prevents you from boosting data rates between PCI cards while maintaining backward compatibility, but start-up Sebring Systems has invented a ring-based connection scheme to do just that. Logically, the Sebring Ring resembles ring-based communication schemes, such as the FDDI (Fiber Distributed Data Interface) LAN. Physically, however, the Sebring Ring acts as a backplane communication scheme that offers significantly greater throughput than traditional buses. The company claims that the Ring can boost bandwidth between two PCI cards by a factor of 30 over the standard 32-bit PCI bus.

A 16-bit, dual-counter-rotating architecture using differential signaling, the Sebring Ring uses ATM-like cells that travel around the ring. At each node, the Sebring Ring Controller IC (SRC3266) either passes cells along the ring or removes cells addressed to its node. The dual rings allow for cells to travel in either direction, although the architecture ensures that cells will take the shortest path between nodes when both rings are fully operational. The dual ring also ensures uninterrupted operation when one of the rings or any single node fails. As in FDDI, the nodes on either side of a failed node automatically connect the two rings, thereby creating one ring and sustaining operation--a concept called self-healing.

The Sebring Ring borrows a medium-access scheme from the SCI (Scalable Coherent Interface). Each node includes dual 512-byte FIFO buffers that act as on- and off-ramps to the ring. A flow-control algorithm limits the amount of traffic each node can generate to each node on the ring. Moreover, a fairness counter in each SRC IC limits the amount of ring bandwidth that a node can use. The scheme results in an average latency of 144 nsec in a 16-node system that employs 66-MHz PCI nodes--a latency figure superior to that of most arbitrated buses. Moreover, the SCI-like scheme allows concurrent operation on the links that form the ring.

Sebring Systems claims that the SRC IC can support an aggregate bandwidth of 4.25-Gbytes/sec in a system with as many as 128 PCI buses. The key to success, however, comes from PCI compatibility and competitive pricing. A Sebring Ring-based backplane is simpler to design than a bus because the relatively short, point-to-point links present no transmission-line problems, even though the links are clocked at 266 MHz. Such a backplane does require an SRC IC for each PCI-bus node. The PCI nodes can be either standard multislot PCI buses or a single PCI slot. Sebring designed the SRC IC to mimic the operation of a standard PCI-bridge IC. Therefore, software running on a host can seamlessly access standard PCI boards across the Ring.

Sebring Systems plans soon to target markets such as servers and network switches and routers. These applications have bandwidth requirements that exceed the capabilities of PCI yet would benefit from the widely used, low-cost PCI cards. Moreover, server vendors can use the technology with the I₂O scheme and seemingly solve bandwidth problems that are plaguing those vendors. The company plans an 8-bit, lower cost version for 1999. That version will use single-ended signaling yet still offer far greater performance than PCI or even technologies such as the AGP (Accelerated Graphics Port) that are dedicated to graphics.

Sebring Systems has lined up an impressive list of partners, including its fabrication vendor, Tritech Microelectronics (San Jose, CA). Other partners include network-equipment vendors, server vendors, and a backplane vendor. The technology also has the potential to move into the desktop down the road. It's unclear, however, whether the technology will ever take over the desktop because Intel (Santa Clara, CA) has yet to voice an opinion on the technology. Still, the Ring should garner significant success in other markets, including embedded systems. For example, the Sebring Ring can greatly enhance Compact PCI system bandwidth and allow any two Compact PCI slots to perform direct DMA transfers.

Moreover, the SRC3266 debuts at $59 (10,000); that price is only double what PCI bridges now sell for in high volume. If Sebring Systems can deliver working technology at that price, it could put the final nail in the VMEbus coffin; VME has already lost significant market share to standard PCI and Compact PCI.

--by Maury Wright

Sebring Systems, Los Gatos, CA. 1-408-358-7827, www.sebringring.com.

Graphics accelerator offers
"business-ready" 3-D

S3 believes it has the right blend of performance and quality for "business-ready" 3-D graphics with its new Trio3D accelerator. The Trio3D also delivers high-performance, 2-D graphics and advanced videoconferencing--both important for business PCs. To complete the package, S3 has cooperated with software partners to introduce 3-D-based business-productivity applications that use the Trio3D capabilities to help users visualize information.

Business-ready 3-D graphics capability provides an affordable mix of performance and quality for corporate and small, home-office PCs. S3 based the 3-D engine on the S3d architecture. The engine delivers low-range to midrange performance, depending on the system's CPU performance in triangle-setup calculations. Rendering features include MIP mapping, trilinear filtering, and perspective correction of textures. Other features include transparency for rendering glass or plastic objects and Z-buffering to speed the removal of hidden surfaces.

The Trio3D accelerator includes a new 2-D graphics engine featuring a 128-bit pipeline architecture, support for 125-MHz synchronous graphics RAM, and S3's burst command interface--a proprietary protocol that works with the PCI or AGP bus--to increase command and data efficiency.

The accelerator manipulates video with blending, scaling, and stretching while displaying dual video windows. In addition, the Trio3D implements the Video Interface Port (VIP) bus to interface to peripherals such as videocameras, TV tuners, and MPEG-2 decoders.

The Trio3D accelerator is available for sampling now and costs $22 (10,000) in 208-pin PQFP or 336-pin BGA packages. The PQFP and BGA packages are pin-compatible, respectively, with previous and next-generation S3 graphics accelerators.

--by Stephen Kempainen

S3 Inc, Santa Clara, CA. 1-408-588-8000, fax 1-408-980-5444, www.s3.com.

Antifuse FPGAs target gate-array ASIC designs

New antifuse-FPGA products from Actel and QuickLogic, although less flexible than flash- and SRAM-based alternatives, offer high performance and abundant routing resources. Actel's MX family combines the dedicated decoding logic, on-chip memory, and JTAG capabilities of the company's 3200DX product line with the PCI compatibility of the A1400 family. Additionally, MX delivers 3.3V PCI operation, a first for Actel. Seven MX family members span 2000 to 52,000 logic gates, and user-configurable output buffers enable either 5.6-nsec clock-to-output performance or low-power operation. The 4000-gate A40MX04 costs $4.90 (50,000), and the 16,000-gate A42MX16 costs $7 (50,000); both are now available for sampling. Other devices will become available in mid-1998.

QuickLogic has migrated its pASIC 2 product line to pASIC 3, a four-layer-metal, 0.35-µm process. This conversion from the previous 0.65-µm process eliminates one nagging criticism of antifuse FPGA technology: that it continually lags behind SRAM-based FPGAs by several process generations. Al-though pASIC3 devices now operate exclusively at a 3.3V core voltage, they retain 5V-tolerant inputs/outputs, and the company provides de-sign-conversion documentation on its Web site. High-end pASIC 3 usable gate counts will reach 100,000, and QuickLogic plans to integrate onboard RAM in R versions beginning in mid-1998. The 25,000-gate QL3025 is now available for sampling. Planned prices for the 12,000-gate QL3012 and 60,000-gate QL3060 are $8.90 and $42 (10,000), respectively.

--by Brian Dipert

Actel Corp, Sunnyvale, CA. 1-408-739-1010, fax 1-408-739-1540, www.actel.com.

QuickLogic Corp, Sunnyvale, CA. 1-408-990-4000, fax 1-408-990-4040, www.quicklogic.com.

ARM tosses in another µP core

The new ARM9TDMI core has a leg up on the previous generation ARM7TDMI and ARM8 cores. Compared with ARM7TDMI, which has a three-stage pipeline, ARM9TDMI features a five-stage pipeline: fetch, decode, shifter/ALU, cache, and write back. Unlike the ARM8, ARM9TDMI includes no prefetch buffer in the fetch stage. Another significant difference between the cores lies in the bus architecture. Whereas the ARM7TDMI uses a Von Neumann architecture, ARM based ARM9TDMI's interface on a Harvard architecture. This feature allows the ARM9TDMI to perform multiple accesses in parallel and reduces the clocks per instruction from 1.9 to 1.5.

To take advantage of the Harvard architecture, ARM9TDMI has forwarding logic, which passes load data into the decoding cycle of the next instruction. The register file has a third read port for accessing stored data; ARM7TDMI's register file has only two read ports. ARM9TDMI also has a separate address incrementer to generate data addresses during load- and store-multiple instructions, freeing the instruction-bus incrementer to continue generating instruction-fetch addresses.

ARM9TDMI contains forwarding logic that can forward-load data into a stalled instruction without first writing the data back to the register file. This feature means that load instructions effectively take only two cycles to execute compared with three cycles for the ARM7TDMI. If the instruction following the load does not need the data, then the instruction can immediately execute, and the load takes only one cycle to execute.

Similar to the ARM7TDMI and ARM8, ARM9 includes a coprocessor interface to allow you to hook up hardware accelerators, such as floating-point and multiply-accumulate units. Both cores can accommodate a Thumb module. With its EmbeddedICE debugging unit, ARM9 expands the on-chip debugging capability of previous-generation ARM cores. EmbeddedICE uses a five-wire JTAG interface to control on-chip debugging logic. It allows you to set up instruction breakpoints and monitor data accesses, and, most important, it requires no debugging monitor code to run. This capability allows you to debug the system's final configuration. You can also use this debugging unit to examine cache addresses and cache contents after the processor stops.

The first two silicon implementations of the ARM9, the ARM940T and ARM910T, contain the ARM9TDMI core, which includes the Thumb module and debugging unit. Both products also contain a 4-kbyte instruction cache and 4-kbyte write-back data cache, a write buffer, a system-control coprocessor, clock-control logic, and the ARM proprietary advanced microcontroller-bus architecture (AMBA). AMBA defines an on-chip bus hierarchy that comprises a high-speed core bus and low-speed peripheral bus.

ARM targets the ARM940T at embedded applications, such as modems and smart phones, and, therefore, includes a simplistic memory-protection unit. Although this unit supports no virtual-memory capability, it provides eight code and eight data regions. Each region has independent size and base addressing, independent cache- and write-buffer enables, and independent access permissions. A priority encoder enables overlapping memory regions. The cache- and write-buffer enables determine the cache- and write-buffer behavior for the corresponding region.

The ARM910T, targeting open applications, such as personal digital assistants, includes the more robust ARM V4T MMU for virtual-to-physical address translation. This MMU, also in the ARM810 and StrongARM110, feature Domains. Domains allow the operating system to switch the protection setup for multiple memory pages in one register write. This feature prevents the OS from flushing the translation-look-aside-buffer and rewriting the page tables for every context switch. The MMU is flexible in the number of 4-kbyte-page to 1-Mbyte-section objects that it can protect, and you can set individual protection attributes on 1-kbyte subpages. This flexibility is important in an object-oriented environment, which has many items of widely varying sizes and properties.

--by Markus Levy

Advanced RISC Machines, Cambridge, UK. 44 1223-400-474, www.arm.com.

USB heats up as data-acquisition bus

As PCs with USB ports are only just starting to appear, Microsoft has announced that it will delay the release of Windows 98, which will be the first widely distributed software to support USB. Undeterred, data-acquisition-hardware vendors are making their expected run at turning the moderate-speed bus that links components outside a PC's system unit into a measurement and data-acquisition platform.

One of the first companies to offer USB-interfaced data-acquisition products is National Instruments, whose DAQPad units previously interfaced to a PC's parallel port. Now, in addition to the parallel-port units, the DAQPad line includes three USB units. Moreover, the company has introduced a $495 USB-to-IEEE-488 converter, whose packaging resembles that of the DAQPads.

One of the DAQPads is an $1195 general-purpose unit that includes 16 single-ended analog inputs, which you can use as eight differential; a 100k-sample/sec, 12-bit ADC; two 12-bit DACs; and eight digital I/O lines. The second is a $695 unit that provides 96 digital I/O lines. The third unit is a $1295, 16-differential-input, 51/2-digit-resolution, temperature-measuring instrument. This unit works with thermocouples (in which case, it accepts 14 inputs), resistance-temperature detectors (RTDs), and thermistors. The instrument takes 10, 50, or 60 readings/sec on one channel and 2.8, 8.8, or 9.7 readings/sec in multichannel mode. The device provides excitation for RTDs and thermistors and includes eight digital I/O lines. You need not rewrite software you developed for different hardware that makes the same types of measurements but that connects differently to the PC.

--by Dan Strassberg

National Instruments, Austin, TX. 1-800-258-7022, fax 1-512-794-8411, info@natinst.com, www.natinst.com.

Current-limited power switch
cuts power-supply size

Short circuits or overload faults at a card slot or plug-in port, such as USB, can pull your system's supply below its minimum operating level. To counter this, you may have to use a current-limited power switch to restrict the external load current, thus preventing excessive drain on your supply. Maxim's 2A, p-channel MAX869L high-side power switch offers 45-mega-ohms typical resistance at 5V and lets you set a current-limit value from 400 mA to 2.5A via one resistor. Its ±20% accuracy, compared to within50% accuracy of other devices, reduces your required design margin for the maximum current your power supply must provide under worst-case conditions, thus reducing its size and cost.

The device includes thermal-shutdown protection as well as a logic-level output that signals a system fault when the device enters an overcurrent or a thermal-shutdown condition. The MAXC869L has a 4-µsec response to prevent system glitches or resets that can occur when you are "hot-plugging"--plugging in a large capacitive load with power on. The 16-pin IC comes in a QSOP, operates from 2.7 to 5.5V, and has 12-µA quiescent current and 0.01-µA current drain when you put the device into its own power-saving shutdown mode. It costs $2.13 (1000).

--by Bill Schweber

Maxim Integrated Products, Sunnyvale, CA. 1-408-737-7600, fax 1-408-737-7194, www.maxim-ic.com.

PCI-to-PCI bridge chips target I₂O,
embedded applications

Digital Semiconductor's new 21553 and 21554 PCI-to-PCI bridge chips ease the design of I₂O subsystems, such as RAID controllers, and the interconnection of processors in embedded-PCI applications. Both 33-MHz chips operate at 3.3V and are 5V-tolerant. The chips enable a PCI-based subsystem to appear to a PCI-based host system as one device requiring one device driver. The chips also allow independent primary and secondary bus-address spaces and can perform address translation between the primary and secondary buses, resolving address conflicts for transactions across the bridge. The 21553 provides a 64-bit primary and a 32-bit secondary bus interface; the 21154 supports a 64-bit primary and a 64-bit secondary bus interface. The 21553 costs $31.30 and will be available for sampling in January 1998; the 21554 costs $36.20 and will be available for sampling in December 1997.

--by Fran Granville

Digital Semiconductor, Maynard, MA. 1-800-332-2717, www.digital.com.

Tiny MultiMediaCard gains support; flash capacity skyrockets

While SanDisk's miniature CompactFlash memory has been busy taking the lead in cameras and other portable devices that need removable flash memory, Siemens (Cupertino, CA) has been out trying to convince the world of the need for the MultiMediaCard (MMC), a much lower cost and smaller memory module. (See "Miniature ROM card targets consumer products," EDN, May 9, 1996, pg 30.) Now, SanDisk joins Siemens in support of the MMC for applications such as music and audio storage and even data storage in ultraportable devices. The MMC differs from CompactFlash in that MMC relies on a much cheaper serial interface and measures only 32×24×1.4 mm--about one-fifth the size of a CompactFlash card. (For more information on CompactFlash see, "Flash targets miniature removable storage," EDN, Jan 18, 1996, pg 42, and "To the victor will go the spoils in the tiny-flash card battle," EDN, Jan 16, 1997, pg 62.) You can also stack as many as 30 MMCs to boost storage capacity.

As partners, SanDisk and Siemens hope to establish the MMC as a standard component in mobile phones, pagers, ultraportable audio players, and other applications. SanDisk will offer flash-based MMCs, and Siemens will offer lower cost ROM-based MMCs. Prices of the flash modules will start at approximately $26 in high volume for a 2-Mbyte MMC. Concurrently, SanDisk also announced the first 80-Mbit flash IC, which will make 60-Mbyte CompactFlash cards feasible and potentially yield higher capacity MMCs down the road.

--by Maury Wright

SanDisk Corp, Sunnyvale, CA. 1-408-542-0500, www.sandisk.com.

Driver for varactor diodes
extends PLL tuning range

Even digital cellular phones need those pesky, sometimes-unusual, analog components, and as supply voltages migrate to 3V, component considerations such as dynamic range become more challenging. The LTC1340 varactor-diode driver from Linear Technology uses a charge pump so that a 3V PLL synthesizer's phase detector output can drive the PLL varactor--which controls the VCO frequency--with a voltage as high as 5V. The device thus yields a wider tuning range with desired linearity. Targeting 900-MHz GSM (Global System for Mobile communications) phones, the driver contains a low-noise amplifier with gain of 2.3; an offset voltage allows the output voltage to swing to ground without 0V on its input.

Maximum output current for device is ±20 µA, and output-referred noise is 15 µVrms to minimize frequency deviation in the PLL VCO. You can set the op amp's bandwidth at 10 to 500 kHz by selecting the value of the output capacitor. The LTC1340 comes in eight-lead SOPs and MSOPs and costs $2.90 (1000).

--by Bill Schweber

Linear Technology Corp, Milpitas, CA. 1-800-454-6327, fax 1-408-434-6441, www.linear-tech.com.

Desktop drives gain performance boost

Seagate just migrated several high-performance technologies into its Medalist family of 3.5-in. disk drives for desktop computers. The new members--models 8641, 6531, 4321, and 2110 with respective capacities of 8.6, 6.5, 4.3, and 2.1 Gbytes--spin the disk platters at 5400 rpm and can transfer data at 33 Mbytes/sec using the new Ultra ATA (AT Attachment) interface. The drives also offer average seek times of 11 msec. Seagate has also added its SeaShield plastic covering for the pc board to help boost reliability and ruggedness. The company expects street prices for the drives to range from $179 for the 2.1-Gbyte model to $495 for the 8-Gbyte model. The company will ship production units this quarter.

--by Maury Wright

Seagate Technology Inc, Scotts Valley, CA. (408) 438-6550, www.seagate.com.

D950 DSP core lands a standard product

SGS-Thomson has introduced the ST18952, its first standard product based on the 16-bit, fixed-point D950 DSP core. (For more details on the core's architecture, see EDN's 1997 DSP architecture directory, May 8, 1997, pg 42.) The chip includes 16.5k words of data memory, 32k words of program memory, an interrupt controller, a DMA controller, a synchronous I/O controller, a timer, a host interface, a bus-switch unit, an emulation unit, and a tap controller. The device also includes an oscillator and a PLL for generating the DSP-core clock. It operates at 3.3V and sells for $18 (10,000). SGS offers a $398 starter kit that contains a board that plugs into your PC's parallel port and has a phone-line interface.

--by Markus Levy

SGS-Thomson Microelectronics, Phoenix, AZ. 1-602-867-6100, www.st.com.

Transparent, wireless RS-232C link
reaches 14 miles using ISM band

Although high-speed links are getting a lot of attention, your application may need distance more than speed. The LAWNII Plus modem from O'Neill Connectivities uses the license-free, 915-MHz industrial, scientific, and medical band to provide a 38.4-kbps-throughput wireless link. The modem spans open-field distances as long as 5000 ft (1500m) with a unity-gain antenna and 14 miles (22.5 km) using a 13-dB gain antenna. Obstructed indoor range is typically 300 ft (91m) with a unity-gain antenna. A point-to-point link requires a pair of these units, each of which comes with DB-9 connector and appears as a standard RS-232C interface device to your data-terminal or data-communication device. You can mount its 4.5×3.5×2.5-in., NEMA 4X, weatherproof enclosure on the antenna mast and visually monitor its status from the ground using its LEDs.

Typical transmitter power is 13 dBm, and receiver sensitivity is ­97 dBm. The units use FSK modulation with 16 chirps/bit and the CSMA/CD protocol. The units require 12V at 250 mA and operate from ­40 to +75°C; they cost $495.

--by Bill Schweber

O'Neill Connectivities Inc, Willow Grove, PA. 1-215-830-1200, fax 215-830-1207, www.ocilawn.com.

Build a low-cost power meter
with power-to-frequency IC core

IC-based meters are putting the squeeze on traditional residential and industrial ac-power meters. The IC devices perform better and have more potential for enhanced features than traditional meters. One IC-based meter, the AD7750 power-to-frequency converter from Analog Devices, accepts two inputs signals, develops their product, and provides a 100-pulse/kWhr output, which can drive an electronic or electromechanical digital readout. The IC comprises two A/D-converter functions, a multiplier, a digital-to-frequency converter, and associated circuitry. Error as a percentage of reading is less than 0.5% over a 500-to-1 dynamic range and less than 0.3% over a 200-to-1 range.

You can use the integral 2.5V bandgap reference or supply an external reference. Both analog inputs are fully differential, with selectable ×1 or ×16 gain on one and fixed gain of ×2 on the other; nominal input range is ±1V. Using the device eases overall system calibration, because the unit provides a high-frequency pulse output to shorten the calibration cycle and provide for offset removal. The AD7750 operates from a 5V supply, comes in a 20-pin DIP or SOIC package, and costs $2.50 (100,000).

--by Bill Schweber

Analog Devices, Norwood, MA. 1-781-937-1428, fax 1-781-821-4273, www.analog.com.

Power MOSFETs blend
high voltage, low resistance

Targeted at industrial and automotive applications, which require higher voltages than cell phones and laptop computers, Harris Semiconductor's UltraFET family of 13 to 75A MOSFETs feature milliohms on-resistance, even at full current rating. The 55V breakdown MOSFETs target applications such as solenoids, motor control, air-bag-firing mechanisms, antilock-braking systems, and fuel injectors.

The HUF753xx series comprises nearly 30 devices with various combinations of current rating, R_DS(ON), and package type. For example, the HUF75345P3 is a 75A device with R_DS(ON) of 0.007ohms at full rated load; it comes in a TO-220AB package. Internal source-to-drain diodes feature fast reverse-recovery times, such as 110 nsec for that device. The MOSFETs, available in through-hole and surface-mount packages, such as TO -220, TO-251/252, and TO-262/263 configurations, also include temperature-compensating and thermal-impedance PSpice models. Prices range from $0.44 to $3.50 (1000); the HUF7534P3 costs $3.40.

--by Bill Schweber

Harris Semiconductor, Melbourne, FL. 1-407-729-4984, fax 1-407-729-5321, www.semi.harris.com.

Digital pot punches through
supply, resistance limits

Electronic digital potentiometers are viable alternatives to mechanical potentiometers in many applications (see "Gain control goes silicon," EDN, May 11, 1995, pg 113). Until now, however the electronic devices have offered only ±5V terminal range and 100-kilo-ohms maximum value. The 7-bit AD7376 from Analog Devices changes that situation. It lets you operate from 5 to 28V single supplies or ±5 to ±15V dual supplies and offers 100-mega-ohm and 10-, 50-, and 100-kilo-ohm values. Applications include industrial, instrumentation, and telecomm designs that inherently need the higher voltage or higher full-scale resistance.

The 128-position potentiometer costs $2.57 (1000) and is available in 1.1-mm-high TSSOP-14, SOL-16, and 14-pin DIP packages. It avoids signal-path noise spikes by eliminating any internal charge pump. The interface to the AD7376 is via a three-wire SPI-compatible connection, and you can daisy-chain multiple devices via the serial-in and -out pins. You can operate the device in rheostat and voltage-divider modes in dc and ac applications. Bandwidth for the 100-kilo-ohm version is 60 kHz, increasing to 520 kHz for the 100-kilo-ohm version. Typical temperature coefficient is ­300 ppm/°C, and operating range is ­40 to +85°C with a 1-µA shutdown current.

--by Bill Schweber

Analog Devices Inc, Norwood, MA. 1-781-937-1428, fax 1-781-821-4273, www.analog.com.

Sine-wave-output motion processors
ease microstepping motor control

Stepper motors provide precise motion control when driven by appropriate signals. The MC1241A chip set from Performance Motion Devices produces two sine waves in quadrature to implement microstepping control of two- and three-phase stepper motors. You control both the amplitude and frequency of these sine waves via internal registers. In addition, the chip set lets you select motion- and performance-profile modes, choosing among S-curve, trapezoidal, velocity contouring, and electronic gearing, all with 32-bit control registers. A motor-control subsystem uses the chip set plus external power amplifiers sized to the motor requirements.

You can use these motion processors with encoder feedback at 32-bit resolution, which also allows you to detect motor-stalling conditions. Alternatively, you can dispense with the encoder and operate the motors in open-loop mode. The chip set, comprising two 68-pin PLCCs, costs $85 (1000) with encoder feedback and $59 without it.

--by Bill Schweber

Performance Motion Devices, Concord, MA. 1-978-369-3302, fax 1-978-369-3819, www.pmdcorp.com.

USB controllers target hubs and peripherals

Intel has expanded the choice of microcontrollers for USB applications with its new 8X931Ax and 8X931Hx ICs. Intel based both ICs on the MCS-51 microcontroller architecture. The 8X931Ax targets PC peripherals and includes 256 bytes of RAM. The IC uses 60% less power than Intel's currently shipping 8X930Ax, supports isochronous data transfers, and comes in ROMless or 8-kbyte ROM versions. The 8X931Hx includes all of the same features and includes support for USB hubs. The IC provides one embedded four external and downstream ports. With 8 kbytes of ROM, the 931Ax sells for $3.50, and the 931Hx sells for $4.30 (100,000).

--by Maury Wright

Intel, Folsom, CA. 1-916-356-6653, www.intel.com.

Line-interface IC brings digital control to
answering machines and cordless phones

Standard low-cost line-interface ICs embedded in answering machines and cordless base stations currently require additional op amps, standard logic ICs, and audio amps to handle analogue speech-processing functions. Now, Philips Semiconductors' UBA1707 line-interface IC offers a single-chip alternative, bringing these analogue functions under digital control and including an on-chip loudspeaker amplifier, microphone amplifier, and electronic hook control. The IC also adapts to any telephone-line standard, enabling you to create a single design to suit applications worldwide.

Four on-chip registers provide complete digital control of IC functions. You can program these registers using a standard three-wire serial bus. The registers control current- and voltage-regulation mode; AGC and slope; loudspeaker volume; channel selection; dynamic limiting; amplifier muting; and power-down modes.

To adapt the IC to a telephone standard, you can program a variety of current- or voltage-regulation modes--with independent control over your product's dc and ac set impedance. Programmable line-current-controlled AGC functions in both transmit and receive channels provide line-loss compensation for a range of exchange-supply voltages. The IC operates on a dc-line voltage as low as 1.2V, which allows you to operate several products in parallel on the same line. The IC also includes drive circuitry for an external solid-state hook switch to provide on/off hook switching, pulse dialing, and timed loop break.

Other programmable functions allow the transmit amplifier to handle input signals of typically 350 to 750 mV on a line current of 15 to 90 mA, respectively. A separate microphone amplifier provides intercom or baby-alarm features. The IC's loudspeaker amplifier has two selectable channels, 3-bit volume control, rail-to-rail output swing, and AGC (if the supply voltage falls below 2.7V). Each channel accepts as much as 500 mV rms for <2% THD. Speaker impedance can range from 8ohms at 3.3V to 16ohms at 5V.

The UBA1707, in an SO28 package, costs approximately $1.15 (1 million).

--by Brian Kerridge

Philips Semiconductors, Eindhoven, The Netherlands. Fax +31 10 458 9196, www.semiconductors.philips.com.

Software starter kit supports low-cost 8-bit µCs

Toshiba's TOPAS 870S entry-level software-development kit provides the essential tools to support the company's TMP87P808N and TMP87PH46N 8-bit µCs. The starter kit comprises a CD-ROM, a PC-connected evaluation board, and one-time-programmable (OTP) device samples. The CD-ROM software includes an ANSI C compiler, a C-like compiler, an assembler, and a Windows-based simulator. The kit also supplies documentation, software examples, and tutorials.

The simulator (designed by AND Software, Theydon Bois, UK) mirrors the behavior of the CPU and peripheral devices, including the ADC, I/O, timers, and interrupts. The simulator allows you to perform source-level debugging; perform forward and backward single step and trace; and test complex breakpoints. The simulator also provides an oscilloscope-type display of I/O-port waveforms. A script file language and test-panel display also show interaction with user hardware.

The evaluation board allows you to program the OTP devices from your PC. The board provides connectors for linking all I/O pins to your own prototype hardware. The two µC samples include a 28-pin TMP87P808N and 42-pin TMP87PH46N. The 28-pin device includes 8 kbytes of ROM, 256 bytes of RAM, an ADC, dual 16-bit timers, and interval and watchdog timers. The 42-pin device adds another 8 kbytes of ROM, 256 bytes of RAM, and two additional 8-bit timers.

The starter kit costs approximately DM200 or £75.

--by Brian Kerridge

Toshiba Electronics, Düsseldorf, Germany. +49 211 52960, www.toshiba-tice.com.

AND Software, Theydon Bois, UK. +44 1992 814655, www.andsoft.demon.co.uk.

VXIbus architecture promotes
low-cost data acquisition

Racal Instruments' 6700 series ProDAQ VXIbus architecture promises more than 50% system-cost savings on a VXIbus data-acquisition system of several hundred channels. In addition, the architecture now promotes VXIbus as a realistic alternative to other board-based data-acquisition systems.

Racal's architecture reduces the number of VXIbus cards you need to build a multichannel system. ProDAQ's key product is a single-slot, C-size VXIbus motherboard module with eight sites that accept a range of proprietary plug-in function cards. For example, a model 6753 VXIbus motherboard with eight plug-ins could provide a VXIbus single-slot capacity of 192 ADC channels, 128 DAC channels, or 384 digital-I/O channels.

The 6753 motherboard allows you to mix plug-in function cards and insert them randomly at any of the eight sites.

Plug-in cards provide 48-channel digital I/O; 24-channel, 16-bit ADC; and 16-channel, 16-bit DAC. The 6753 motherboard costs £1300, and plug-ins cost approximately £600 to £900.

--by Brian Kerridge

Racal Instruments, Slough, UK. +44 1628 604455, www.racalinst.co.uk.

DSP PCI board delivers 3200 MIPS

Loughborough Sound Images' PCI/C6600 PCI board combines dual TMS320-C6201 DSPs, delivering 3200 MIPS of 16-bit integer performance running on a 200-MHz clock. The primary DSP processes data and acts as a data router with access to a PCI interface, a proprietary 33-Mbyte/sec DSPLink2 parallel link to other system boards, and TMS320C4x parallel communication ports. The secondary DSP only processes data.

Each processor has 128k×32-bit zero-wait-state SBSRAM, as much as 4-Mbyte×32-bit single-wait-state SRAM, and 512-kbyte flash memory. The processors communicate using their enhanced buffered serial ports and a FIFO-buffered connection between their external memory interfaces. In addition, the primary DSP can directly access the memory of the secondary processor using its host-port interface.

The board also provides a 132-Mbyte/sec local PCI bus for an IEEE 1386 PMC module to add further processing, memory, or I/O. A PCI-to-PCI bridge interfaces the host and onboard buses and allows the PMC module and primary DSP to transfer data to and from host-PCI resources.

The company's IDE6000 support package provides host and DSP tools, utilities, and libraries. The PCI/C6600 costs approximately $7245.

--by Brian Kerridge

Loughborough Sound Images, Loughborough, UK. +44 634444, www.lsi-dsp.com.

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