MicroTCA takes the AdvancedTCA high-speed serial interconnect to an all time low. Lower power. Lower price. Lower rack size—all pretty good lows. It uses Advanced Mezzanine Card (AdvancedMC) modules like this one from Artesyn (see the figure).
The Kosai PM hides a 1.4-GHz Pentium M under the fins and up to 2 Gbytes of socketed double-data-rate (DDR) DRAM with error-correction coding (ECC). The card has a USB and serial port plus PCI Express connectivity to the backplane.
Originally designed for an AdvancedTCA baseboard, this fullheight, single-wide, hot-swappable singleboard computer can be the centerpiece of a MicroTCA system. Compared to Advanced-TCA racks, these smaller systems can sit in back offices or embedded in medical equipment. Or, they can serve as wireless basestations where reliable, robust, high-speed interconnects are needed. Intelligent Platform Management Interface (IPMI) support is a handy side benefit.
MicroTCA isn't the only form factor vying for compact applications. 3U CompactPCI, VME, and even EPIC Express fit into this category, though EPIC Express isn't suitable for hot-swapping cards. So why is there yet another standard? Actually, most of the work is done already.
AdvancedTCA requires the AMC standard. It only needs to take standard connectors and mount them in a backplane of a card cage instead of a carrier board. The proposed MicroTCA standard took a great deal of work, but that's more a matter of details than any stunning technological breakthrough.
This architectural reuse will enable MicroTCA to come online more quickly than AdvancedTCA, which is still in its infancy. The AMC cards designed for the AdvancedTCA environment will work equally well in a MicroTCA system. There likely will be cards targeted only at MicroTCA, but there is no reason why they wouldn't work on an AdvancedTCA system. Rather, the on-board peripheral mix will be different, with MicroTCA tending toward higher integration and allowing the use of smaller MicroTCA racks.
The big question is whether or not MicroTCA will emerge from its communication roots and address applications in data acquisition and industrial control. It's the right form factor, but it will require cards that are all but useless in most AdvancedTCA systems. Likewise, MicroTCA will have to compete with existing board standards that already have peripheral cards to support these markets. Either way, MicroTCA looks like a winner.