FPGA board for avionics applications designed by MEN Micro

AMBLER, Pa., 4 Sept. 2010. MEN Micro Inc. now offers the 6U field programmable gate array (FPGA) -based, triple-redundant A602 64-bit VMEbus single board computer (SBC) that uses a lock-step architecture keeping software development at a minimum for avionics applications.

The A602 runs the same set of operations in parallel to ensure that the programming only views the hardware components once, Men Micro officials say.

The single-slot, commercial-off-the-shelf (COTS) A602 developed according to RTCA DO-254 offers reliability and economical implementation with high reliability up to Design Assurance Level (DAL) A (catastrophic) in avionics and up to Safety Integrity Level (SIL) 4 in trains -- the most stringent level in each class.

The 900 MHz PowerPC 750, the 512-megabyte main memory and the internal structure of the FPGA are triple-redundant. Critical functions, such as voters implemented as IP cores in the FPGA, monitor at least two of the three redundant components to provide the same result to guarantee system reliability. In the event one of the three redundant components fails, the system remains completely operational providing the required availability for highly critical systems.

Other redundant components in the SBC include local PSUs, Flash memory and clock oscillators. In an effort to increase safety and availability, additional diagnosis mechanisms (BITE, e.g. extensive self tests) help detect latent errors before they lead to a system error. The design is oriented towards strictly deterministic operation for the same purpose -- to avoid interrupts and DMA.

Standard I/O contained in the FPGA is accessible via the rear and this includes a sextuple UART, an I2C bus and an RS232 interface that can also be led to the front. The A602 also provides two PMC slots, one accessed via the front or rear I/O that can be used with all standard PMC modules and the other for an AFDX PMC connection via rear I/O.

Operating temperature is -40 to 50 degrees Celsius with qualified components. Pricing for the A602 is $12,994.

For more information visit http://www.menmicro.com/products/01A602-.html.

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Dawn of a New Age in Serial Switch Fabrics

By John Keller
Editor in Chief

We stand on the doorstep of the next generation in serial data switch fabric networking, which will see vast speed increases from today's data processing. The dominant switch fabrics of today–Gigabit Ethernet, PCI Express, and Serial RapidIO–all are ready to move to even faster versions, which promise fundamental leaps in embedded computing power.

Systems engineers, meanwhile, are finding innovative uses for point-to-point communications links called Aurora and SerialLite for field-programmable gate arrays (FPGAs) from Xilinx and Altera, and are even finding new value in old standbys.

Switch fabric technology is a godsend for embedded computing designers who increasingly realize that parallel databuses like VME 64 simply are no longer adequate for today's high-end aerospace and defense applications in electro-optical sensor processing, software-defined radio, signals intelligence, and radar signal processing.

Switch fabrics represent the next step in intra- and inter-system data communications in high-end and complex systems. Switch fabrics blend hardware and software to move data into a network that joins sensors, single-board computers, and central processing units to move data coming into a network node out by the correct path to the next node in the network. Without this kind of technology in today's world of high-speed central processors, data bottlenecks and roadblocks likely would proliferate through complex signal processing and cause crippling delays by a failure to move information quickly enough to keep up with processor capacity.

While switch fabrics have enabled systems designers to take the next steps in signal processing capability, the next generations will help move data and signal processing ahead even more. Gigabit Ethernet technology is enabling high-speed control and monitoring of complex data processing. While 1-gigabit and 10-gigabit Ethernet implementations are commonplace in switch fabric networks, 40- and 100-gigabit Ethernet implementations wait in the wings not only to speed control, monitoring, and predictive maintenance forward, but also to provide more options and standardization for designers of high-speed systems.

Several years ago, the PowerPC microprocessor architecture helped revolutionize digital signal processing (DSP) applications. Prior to that, designers had to use separate dedicated DSP chips and general-purpose microprocessors. The PowerPC enabled them to perform separate tasks with the same kind of chip to simplify programming, acquisition, maintenance, and technology insertion.

Gigabit Ethernet technology could offer similar advantages. While complex switch-fabric based computer systems use Gigabit Ethernet, PCI Express, and Serial RapidIO separately for different tasks within the system, Gigabit Ethernet as it moves into the 40- and 100-gigabit realm may enable designers to implement several different high-speed data paths with the same networking technology. Depending on the application, Ethernet used on several layers of the OpenVPX Multiplane Architecture or similar design approaches could help simplify designs and reduce life cycle costs. Where Ethernet technology is not appropriate, the next generations of PCI Express, RapidIO, and even InfiniBand are ready to become available.

Where switch fabric architectures are concerned, systems designers are looking forward to more speed, less cost and complexity, and easier upgrades and technology insertion. Couple that with new generations of tools like POET from Mercury Computer Systems, and the future of switch fabric architectures looks bright indeed.

PCB |PCB Design Software |PCB Electronics |Printed Circuit Board |

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Automated inspection in printed circuit board assembly (PCBA) manufacturing

Visual inspection has long been a necessary method of quality control in Printed Circuit Board Assemblies (PCBA) manufacturing. The characteristics of electronic assemblies have changed substantially over the last decade. Todays high lead count, fine pitch SMT components are becoming even more difficult for humans to inspect at the same time automated inspection systems have become reliable than manual inspection and are now accepted as valuable tools for producing high quality PCBA products. The basic requirements of an automated inspection system remain same in all PCBA manufacturing but the type of the automated system (off- line/on-line), where applied in the production flow, entire boards or only on a sample basis, inspection coverage (100% or partial) vary between different PCBA manufacturers. In PCBA manufacturing the emphasis is more in the electrical functionality of the PCBA than in it's appearance. It is nearly impossible to impose stringent specifications in the appearance of the components and other materials used in PCBA manufacturing. Due to the large number of component/PCB supplier and wide variations in materials and processes the challenge in successfully automating the inspection process is the variability in the appearance of components on PCBA. But in a high volume PCBA manufacturing where fewer board types are running in large volumes for long periods of time, the variability in component appearance can be controlled much better than a low volume PCBA manufacturing where more types are running in low volumes for short period of time. This paper discusses the development and implementation of a low cost flexible automated inspection system for PCBAs. The system can detect over ninety percent of visual defects on PCBAs. The key features of the system are quick and easy set-up, capability to inspect different types of board and quick change over between different boards and low cost.

PCB Circuit Boards
PCB Electronics

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Which Laptop battery is right for you?

The short answer is: “Whichever type fits your laptop.”

Laptop batteries vary according to the model and type of laptop computer for which they’ve been designed. All laptop batteries do, however, share some common characteristics that differentiate them from regular household batteries:

• Laptop batteries are rechargeable
• They are composed of multiple internal cells
• Within each laptop battery is a small printed circuit board
• Shape and location of terminals differ from model to model.

As is the case with all batteries, laptop batteries create an electrochemical reaction, forcing a stream of electrons from one position to another. Also like other batteries, laptop batteries have positive and negative terminals that receive and send electrons.

Rechargeable batteries are more complex, however, than standard batteries. This is because the electrochemical reaction that provides power must be reversible. Care has to be taken when recharging them to ensure they perform at their best.

Frank McLarnon, Lawrence Berkley lab’s staff scientist explains it this way to Scientific American.com:

“When a battery is discharged, an electrochemical oxidation reaction proceeds at the negative electrode, and an electrochemical reduction reaction occurs at the positive electrode. When one attempts to recharge a battery by reversing the direction of electric current flow, the opposite takes place: a reduction reaction proceeds at the negative electrode, and an oxidation reaction takes place at the positive electrode.

In the case of the rechargeable battery, the electrochemical oxidation-reduction reactions are reversible at both electrodes. In the case of the non-rechargeable battery, when one attempts to recharge the battery by reversing the direction of electron current flow, at least one of the electrochemical oxidation-reduction reactions is not reversible. When the battery is charged, the overall reduction reaction that proceeds at the negative electrode may not be the true reverse of the oxidation reaction that proceeded when the battery was discharged.

If the laptop battery process isn’t exact, then unwanted build up can take place on either terminal over time, which can cause a dangerous short-circuit.”

It is so important to ensure that your laptop battery or notebook battery is the one designed for your particular model and type. Only buy Dell laptop batteries for a Dell laptop computer, Gateway aren’t compatible with Compaq laptop batteries and Toshiba laptop batteries won’t sit well in a Sony.

It is also wise to remember that old adage: “You get what you pay for.”
Some companies offer used “cheap laptop batteries” for sale, saying that they have refurbished each battery and restored most of its useful life. The fallacy of this is that, although possible to refurbish a second-hand laptop battery, the cost to do so would be more than the price of a new battery. So, “Buyer beware,” and if you must buy discount laptop batteries, buy new discounted batteries.

Laptop computers are a boon to business, large and small. As a wise person is just about to say: “Look after your laptop and it will look after you.”

Printed Circuit Board

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