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September 11, 2014

AdvancedTCA Extensions (PICMG 3.7) Update

PICMG

The AdvancedTCA community is nearing completion of a fairly major enhancement to the core ATCA standard. This new specification is known as “PICMG 3.7” or “ATCA Extensions.” It expands the packaging definitions to include dual sided shelves, where ATCA boards can plug into either the front of the back of a double-deep rack and interconnect through a single or dual backplanes. Both vertical and horizontal board orientations are defined. In addition to this, the Extensions specification also allows for something called Extended Transition Module (ETM) that is essentially a front board-sized circuit board that connects to a front board via Zone 3, much like a standard Rear Transition Module.

These new mechanical configurations significantly expand the flexibility and versatility of ATCA. The double-deep configurations can make better use of available rack space when compared to single-deep systems.

There are many variations of interconnects allowed, but Figure 1 below gives a general idea of the concept.

advancedTCA extensions

Importantly, PICMG 3.7 provides a much more detailed definition of, and support for, double wide modules than the original specification. These can support multiple processors, bigger heatsinks, cheaper full height memory modules, and multiple disk drives on a single assembly if desired. PICMG 3.7 also defines requirements for typical data center environments in addition to the telecom central office. Double wide modules can support up to 800W of power dissipation if the shelf is built for that. AC as well as traditional -48VDC power environments are also supported. PICMG 3.7 also provides a much more rigorous definition of the thermal environment within a shelf and provides useful guidance for those designing high power systems.

 

 

September 11, 2014

CompactPCI Serial Revision 2 Update

PICMG

The CompactPCI Serial standard has become a popular platform for a variety of applications requiring modularity, high performance, and symmetric multi-processing. It is being used for a wide range of industrial control, communications, data acquisition, mil/aero, security, and medical applications. Using modern serial interfaces including Ethernet, SATA, and USB 2.0/3.0, CompactPCI Serial provides data transfer rate improvement of about 20x over original CompactPCI.

A technical subcommittee has just completed work on a second revision of this flexible platform. It increases capability by providing direct rear I/O over the P6 connector enabling economical low end solutions. Up to three complete CompactPCI Serial single board computers can co-exist on the same backplane and communicate via Ethernet without the need for bridges or switches. Full mesh systems with up to nine processors are still supported using the appropriate backplane topology. Backwards compatibility with existing CompactPCI and CompactPCI Serial boards is maintained, also via backplane topology.

This new revision is expected to be released in Q4, 2014.

The committee is also working on another document that defines a simple, IPMI-based management subsystem that will be much simpler than the management infrastructure defined for ATCA but will provide basic diagnostic, maintenance, and security functions. This work is expected to be completed by early 2015.