Has VME Learned From xTCA?
Despite VME guru Ray Alderman’s (in)famous comment that CompactPCI was a “dog” and ATCA a “dog with fleas,” it appears that VITA and the VME industry may be moving along a path first blazed by PICMG and xTCA.
Late in 2002, PICMG released the first version of the Advanced TeleCommunications Architecture (ATCA) standard. This defined the first true blade-based architecture, wherein all communication across the backplane was via a high-speed serial switch fabric, rather than over a shared, parallel, multidrop bus. This was followed by the Advanced Mezzanine Card (AMC) standard in 2005.
It didn’t take folks that long to realize that AMC cards could also be used as blades in smaller footprint systems. PICMG released the first version of the resultant MicroTCA standard in 2006. The advent of MicroTCA was seen as a positive development for the market, not only because of its technical capability and reduced footprint (vs. ATCA), but because it also expanded the potential market for AMC cards. These could be used either as mezzanine cards or as MicroTCA blades, yielding higher potential volumes and thus greater economies of manufacturing scale.
The VME industry was slower to adopt blade-based systems architectures, largely because military and aerospace defines the primary market for VME systems, and the military tends to take a more cautious approach to innovation than do civilian markets. In the latter, time-to-market is of overarching concern, whereas in military and aerospace, where mission criticality is the primary concern, far more emphasis is placed on reliability and ruggedness.
However, the evolution of VME through VME2eSST and VXS to VPX and OpenVPX has brought blade architectures, similar to ATCA, to the forefront of VME-based technology. It now appears that parallels to AMC and MicroTCA are also in the works.
Two new small form factor systems architectures are currently being investigated by VITA, with the objective of producing standards. These are “micro.VPX”and “NanoATR.” The former is the brainchild of PCI-Systems, Inc., and is the subject of working group VITA 73; it utilizes a small form factor VPX card. The latter, NanoATR, was developed by Themis Computer, targeted at ATR systems for aircraft, and utilizes an even smaller card. NanoATR is the subject of working group VITA 74. Both versions of the cards are being evaluated by the VITA 71 working group, which is developing a standard for a new rugged VME mezzanine architecture.
VDC believes that these developments will be highly beneficial to the VME-based ecosystem, and applauds the effort. Development of the MicroTCA standard was, however, fraught with confusion and delay because of differing views on an optimal configuration (cube vs. rack mount). We caution VITA’s working group(s) against falling into a similar trap, and to allow either configuration from the start.