Control Engineering Embedded Control eNewsletter for July 2003
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ASIC versus FPGA issues
Application-specific integrated circuits (ASICs) and field-programmable gate arrays (FPGAs) present alternative design approaches for embedded control designers.
Each approach offers tempting tradeoffs: ASIC advantages include high-performance features, lower power usage, and robustness of a custom chip product, which come at a price due to the associated upfront costs. However, ASICs require longer development times and also commitment to a specific chip design or target application without the luxury of reprogramming.
On the other hand, FPGA's strong suit is design flexibility. Inherent ability to be reprogrammed allows faster design cycles and lower costs depending on unit volumes. Downside tradeoffs here include more power consumption and higher recurring costs that become a factor at high volumes.
Fresh developments add to the mix of user options available as the following two examples illustrate.
MathStar Inc. (Minneapolis, MN) has recently announced its so-called field-programmable object array (FPOA) architecture, which reportedly offers ASIC performance at FPGA prices. FPOA architecture is based on the company's patented Silicon Objects technology, which claims cycle time of 1 GHz “with no timing closure” as well as the ability to be field reprogrammed. These “objects” are 16-bit configurable devices akin to arithmetic logic units or multiply-accumulators, yet have a uniform I/O structure, according to MathStar.
Also from MathStar, NoGates design tool environment complements the FPOA architecture to simplify device synthesis and gate-level layout. Mid-volume applications with unit costs closer to ASICs than FPGAs are the current targets for FPOA chips; however, pricing was not stated at this point. NoGates tool is available for customer evaluation; product samples are set to follow in Q403.
A related development from Altera Corp . (San Jose, CA) seeks to provide middle ground between ASIC and FPGA approaches. The company's recently introduced HardCopy Stratix devices enable a mask-programmed version of an FPGA design, which users can target directly from the start of design.
Based on the Altera's Stratix FPGA architecture, HardCopy is a second-generation technology said to run 50% faster on average. These low-cost, mask-programmed devices retain normal FPGA features, such as hierarchical clock structure and embedded digital signal processing blocks. However, the FPGA's programmable part is removed to obtain performance closer to ASICs at half the cost of FPGAs, says Altera.
Software to support HardCopy has recently been enhanced as well. Quartus II version 3.0 software provides a design path for either FPGAs or mask-programmed ASIC-like devices. In the latter case, users can develop HardCopy devices directly without the need for prototypes. Among improvements added to the latest version of Quartus II is a suite of system-level design features.
Hot-swappable controller chip for cPCI applications
LTC4240 chip is available in temperature ranges suitable to industrial and commercial applications.
Linear Technology (Milpitas, CA)—a manufacturer of high performance linear integrated circuits—introduced LTC4240, an I2C Hot Swap controller chip that allows safe insertion and removal of a board from a live CompactPCI (cPCI) bus slot.
LTC4240 controls all four CompactPCI voltage supplies. This is accomplished through two external N-channel transistors for the 3.3 V and 5 V supplies, plus two on-chip switches that regulate the
Software control and monitoring of device functions as well as power supply status is featured via a built-in, two-wire I2C-compatible interface. Users can turn the device on/off, set RESETOUT, turn on a status LED driver, and ignore
LTC4240 comes in a 28-pin narrow SSOP (shrink small-outline package) size, with price starting at $4.25 each for 1,000-piece quantities.
Partnering on high-density cPCI serial card: Kontron, Comtrol
Kontron expects to make RocketPort serial card available immediately, with production units selling for $995.
Reportedly the industry's first 16-port CompactPCI (cPCI) serial card with a 3U height is a result of a cooperative development effort between embedded computer technology company Kontron (Hayward, CA; Eching/Munich Germany) and Comtrol Corp. (Minneapolis, MN), a U.S. provider of multiport serial-to-Ethernet device connectivity and management products.
Called RocketPort, the card was developed through use of Kontron CP302 Intel Mobile Pentium III processor-based CPU board and CP-ASM-4 cPCI chassis. The serial card conforms to the PICMG 2.0 Revision 3.0 specification for cPCI expansion cards within PCI industrial computers. RocketPort supplies up to 16 high-speed RS-232/422 connections from one cPCI expansion slot.
Management from both companies is keen on this joint product development, which results from previous close relations. From Kontron's view, intelligent serial products such as those from Comtrol are “a great fit” for the CompactPCI platform, which is intended to satisfy high-reliability applications. For Comtrol, the need for high-performance serial technology expressed by Kontron's customers provided the reason to enter the new market.
Think about embedding a PLC board
Part of designing any system with a controller is ensuring usefulness after it leaves your hands. For future platform stability for your next embedded application requiring logic, you should consider using a programmable logic controller (PLC) in a board form factor, suggests Jeffry W. Jurs, manager, Omron Electronics Engineering Center, in St. Charles, IL. One integrated circuit and a few other components give a PLC its behavior. All the rest of the package, outside the board, Jurs explains, is for the interface to sensors, actuators, and serial communication devices. Since Omron makes the core PLC chip, ''We're not subject to the whims of the semiconductor industry,'' ensuring that the hardware is secure and stable. ''This chip has been used in hundreds of thousands of products. Quality, stability, and the programming environment are always among concerns when designing any embedded application. There's no wondering about the behavior of this embedded PLC board,'' Jurs says.
''The programming software works on this board and the rest of Omron's PLC family. Different from 'typical' embedded systems that program in 'C,' these boards program with standard graphical relay programming language. Also, online editing and download capabilities mean you don't have to stop the machine to program and compile changes. From a business perspective, it's nice to have a big company like Omron there for support,'' he adds. Jurs made the suggestions to Control Engineering 's Mark Hoske at the recent Technology Connection at Omron's North American headquarters in Schaumburg, IL.
While Jurs didn't mention specific products during the conversation, related references on the Omron site include:
For more about Control Engineering 's coverage of the symposium, click on:
Worth reading: Streamlining embedded designs
A recent book, ''Embedded Systems Design on a Shoestring: Achieving High Performance with a Limited Budget'' (ISBN 0-75067-609-4) by Lewin Edwards, is bound to be of interest to embedded controls professionals.
Tight schedules and budgets in today's project environments put great pressure on embedded systems designers to speed up their designs and produce prototypes quickly while holding costs. Lewin Edwards, an experienced embedded engineer at Digi-Frame Inc . (Port Chester, N.Y.), offers practical guidance and tips on faster, lower-cost methods for developing high-end embedded systems in this 304-page paperback book. How the use of the right tools and operating systems to navigate seemingly impossible deadlines are demonstrated.
The book and accompanying CD-ROM that includes useful open-source tools for embedded design sells for $49.95 and is available from Newnes Press, an imprint of Elsevier.
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