MicroTCA: High performance in a small package

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December 01, 2006

MicroTCA was originally conceived as a smaller, lower-cost cousin to AdvancedTCA, and telecom as its primary market. Since the specification has been ratified, a high degree of interest for nontelecom applications has surfaced. Prime among them are military applications.

MicroTCA is a new open computing standard developed by PICMG that provides high performance and modularity. However, it is physically small enough to be used in a variety of mobile military applications, including vehicle and airborne platforms. MicroTCA uses the new AdvancedMC mezzanine cards that were originally designed for AdvancedTCA applications but uses them in a different way. AdvancedMC cards provide high performance in a small package. They are fabric-based and can use PCI Express, Ethernet, or RapidIO for high-speed data transfer. They are also fully managed and hot swappable, making them ideal for high-availability applications where systems resources can be made redundant so that cards can fail and the system keeps operating. In MicroTCA, AdvancedMCs (see Figure 1,  courtesy of GE Fanuc Embedded Systems) plug directly into the system backplane, whereas they typically plug onto a carrier card in AdvancedTCA applications.

Figure 1: In MicroTCA, AdvancedMCs plug directly into the system backplane, whereas they typically plug onto a carrier card in AdvancedTCA applications

(Click graphic to zoom by 1.3x)

MicroTCA provides a high-performance multiprocessor architecture that supports CISC and RISC processors, DSPs, FPGAs, and network processors simultaneously. Data throughput exceeds 10 Gbps per slot, so MicroTCA is ideal for applications requiring lots of data manipulation and transfer, including voice, image, and radar processing. The MicroTCA backplane supports star, dual star, and full mesh topologies.

The MicroTCA architecture is very scalable. Simplex systems with single resources can be built quite inexpensively and are suitable for applications where low cost is critical and occasional failures can be tolerated. Duplex systems with redundant cards and high-availability software are more complex and expensive, but can offer 5 Nines availability, 99.999 percent uptime.

Military electronic systems designers are rapidly warming to the concept of availability, borrowed from the telecom world where systems are often expected to operate continuously for 30 years or longer. Simple Mean Time Between Failure (MTBF) calculations, which are often little more than an estimate of how often systems might fail, are increasingly viewed as insufficient for the job at hand. The underlying concept of availability is that the system provides redundant hardware and software management such that no single element can be a single point of failure for the entire system. In a highly available system, single elements, payload cards, and power supplies can fail and be replaced at a convenient time without bringing the system down. Because MicroTCA is a switched fabric architecture and not a parallel data bus such as VME or CompactPCI, sys-tems can be designed in a way that a single card failure need not bring the entire system down. The hardware management structure of MicroTCA is largely borrowed from the well- wrung-out AdvancedTCA management architecture. Industry standard high-availability middleware, defined by the Service Availability Forum, can be used.

MicroTCA was originally conceived as a smaller, lower-cost cousin to AdvancedTCA, and telecom was viewed as its primary market. Since the specification has been ratified, a high degree of interest for nontelecom applications has surfaced.  Prime among them are military applications. (Refer to our sister publication PC/104 and Small Form Factors: “Rugged MicroTCA: A swappable alternative”.

While MicroTCA is ruggedized to telecom standards for shock, vibration, temperature, earthquake, and so on, it is not yet ready for the extreme requirements of the mobile military environment. But a number of PICMG member companies are working on developing concepts that range from cocooning a MicroTCA chassis inside an ATR box with shock mounting and conduction cooling (shown in Figures 2 and 3, courtesy of Hybricon Corporation).

Figure 2: cocooning a MicroTCA chassis inside an ATR box with shock mounting and conduction cooling" width

Figure 3

(Click graphic to zoom by 1.3x)

At least one PICMG member company is working on metal clamshells that encase AdvancedMC cards and are then rigidly mounted in a special chassis and directly conduction cooled. It is expected that this work will move into PICMG and become a formal specification development activity at the end of 2006. A lot of work remains both in terms of defining the requirements and then designing a so-lution, but the wide range of expertise in PICMG’s 300-strong membership will be brought to bear as usual.

You can learn more about MicroTCA and its architecture in another OpenSystems Publishing publication, CompactPCI and AdvancedTCA Systems magazine.

For more information, contact Joe at [email protected].

Editor’s Note: As we went to press, Motorola announced $1.0 million in MicroTCA product sales – a significant milestone event.