About MicroTCA 

 

Introduction

With over 30 years of computer bus technology, a new culmination is on the horizon called microTCA. This technology combines the diverse requirements from the telecommunication industry with the industrial automation market. And this combination makes it special in a broad sense, including:

1. Based on high speed serial communication channels, supporting hot swap and providing reliability
    till 99,999% uptime 
2. Scalable infrastructure – from one processor systems to 100’s
3. Small sized cards, suitable for a broad industry – from embedded to industrial control
4. Flexible systems by defining several packaging formats, suitable for different space requirements
5. System management functionality build in, providing the basis for remote diagnostics and maintenance
6. Ruggedized systems, yet low cost capabilities 

With this remarkable combination, microTCA provides a basis for flexible, extendable, low cost controller platforms with high availability and remote maintenance, important to the industrial world. However, it also provides low cost communication controllers build on existing technology (PICMG Advanced Mezzanine Cards, or AMCs) for the telecommunication industry, outside of the typical telecom equipment manufacturers, or TEMs.

 

The basis of microTCA

 The organization PICMG developed an Advanced Telecommunication Computing Architecture, called AdvancedTCA or ATCA, in order to supports the high requirements from the high-end telecommunication industry, especially in the 99.999% system uptime.

In order to provide extensions capabilities to the AdvancedTCA modules, PICMG defined the Advanced Mezzanine Cards, or AMCs. These had to support hot swap and management functionalities, in order to realize the high availability of the ATCA modules and systems.

The next step was to provide the AMC with a backplane of their own, creating the possibility to build systems with just AMC modules. 

 

 

Single width AMC module/backplane combination

 

MicroTCA is designed to address cost sensitive and physically smaller applications with lower capacity, performance, and perhaps less stringent availability requirements. MicroTCA preserves many of the important philosophies of AdvancedTCA, including basic interconnect topologies and management structure.

        MicroTCA Block Diagram of a System

If we look to the system above, we see at the bottom 12 AMC’s that are connected via the backplane. On top we see (from left to right):  

Overall, the basic specification, called microTCA.0, defines the general mechanical, electrical, thermal, and management properties of a microTCA shelf necessary to support AMC compliant modules. Accompanying standards like microTCA.1 – n define the different interconnect protocols in the backplane.

 

Flexibility in mechanical sizes

MicroTCA supports four different mechanical sizes of AdvancedMCs. The largest is the Full-Height, Double-Width AdvancedMC, which occupies a mechanical volume of 150 x 187.3 x 30.48 mm.  

AMC Module configuration examples  

Be aware with AMCs that, as they originated as mezzanine modules, the width is the height of the board size, and the height deal with the width of the front panel if vertically mounted.  

Double-Width, Full-Height Slot dividing examples

 

MicroTCA enclosure types

The standard microTCA elements can be assembled into many different types of systems that conform to the specification. Although the variability of these systems is large, it is believed that in the end there will be a few popular implementation types.

In order to provide more concrete illustrations of how to assemble the standard elements into actual systems, several possible solutions are presented hereunder. Be aware that there are more possibilities as shown here.

 

MicroTCA packaging  

Or other form factors like this single cube on a mounting plate:

 Or even smaller like pico on a panel

MicroTCA design goals

Overall, the PICMG MicroTCA specification was written with the following design goals in mind:

• Complementary to AdvancedTCA
• Full conformance with the AMC.0 Module definition
• Favorable cost, size, and modularity
• Target low start-up costs
• Scalable reliability and bandwidth
• Modular and serviceable
• Standardized Shelf management implementation compatible with AdvancedTCA
• Support 300 mm nominal equipment Depth and 19 in. nominal equipment width
• Cooling: 20–80 W/AdvancedMC
• Support for extended temperatures (–40 to +65 degrees)
• Power: 12 V to AdvancedMCs, in conformance with AMC.0
• Life span: eight years
• Backplane bandwidth: SerDes @ 1–40 Gb/s
• Backplane topologies: Star, Dual Star, Mesh
• Scalable system reliability: from .999 to .99999
• Support any/all AdvancedMC-defined form factors
• Hot Swap/plug-and-play support, in conformance with AMC.0 and consistent with AdvancedTCA


Conclusion

MicroTCA provides a very flexible building block for cost sensitive application and/or with limited space requirements versus ATCA, CPCI or VME. Based on the constructs of all these busses, and building on the existing ATCA mezzanine card market (AMC), a bright future is foreseen for this new modular approach.

A more detailed description of the microTCA specification is available here.

Review the short form version of the  microTCA specification, 

The complete specifications can be obtained from PICMG Europe by using our order form.