AdvancedTCA brings a host of new, high-performance switch fabrics into the communications market. But, it's designed for big racks with lots of cards. It comes as no surprise that a smaller version is in the works, namely MicroTCA, which uses the Advanced Mezzanine Cards (AMCs) designed to plug into AdvancedTCA carrier boards. A typical single-board computer (SBC) may have one or two AMC slots, while a full-size carrier board can handle eight single-wide or four double-wide cards.
The proposed MicroTCA standard initially targets a much smaller rack than AdvancedTCA. It's a 4U card cage that's only 300 mm deep. Also, it will employ the same kind of switched backplane architecture used in AdvancedTCA that currently supports Ethernet, RapidIO, InfiniBand, PCI Express, and StarFabric. In the future, it will support Advanced Switching (AS). The AMC standards add specification support for Fibre Channel and Serial ATA (SATA). The 4U form factor handles the double-wide cards, so it's possible to eventually have an even smaller standard that accommodates only single-wide cards.
A MicroTCA system will use the same architecture as AdvancedTCA. Thus, a system will have at least only one switch card to handle the fabric. It will support the Intelligent Platform Management Interface (IPMI) also found in AdvancedTCA. This increases the manageability of the smaller systems without incurring new development costs, because the same software will be used on MicroTCA and AdvancedTCA systems. IPMI provides power management as well as system-monitoring features.
AMC cards are rated at 35 W. They can have up to 21 ports (42 pairs of pins) for switch-fabric connections and high-speed interfaces such as SATA. AMC cards are hot-swappable, providing flexibility for upgrades and board replacement.
MicroTCA will offer a more compact and robust solution for systems that reside outside of the communications center. It's small enough to fit into vehicles and equipment, such as medical imaging systems, which require high-performance communication and computational power. MicroTCA will enable developers to take advantage of boards developed for AdvancedTCA.
Of course, all of this is subject to change, as the AMC standard is finally solidifying and MicroTCA is built on that. Still, this is one standard being supported by a large group of companies because of its significant benefits and minimal impact on existing standards. Check out the PCI Industrial Computer Manufacturers Group (PICMG) at www.picmg.org for more details on AMCs and related standards.