Teaching old dogs new serial I/O tricks on CompactPCI
A full-mesh architecture for Ethernet applications supports up to nine boards (eight peripherals plus one system board) with no bridges, switched fabrics, or special backplanes required.
It is much easier to build multi-processing systems based on Ethernet, and the system slot is no longer a potential single point of failure, since every board can communicate with every other board directly without a switch (full-mesh).
The Ethernet is based on 100/1000/10GBaseT standard. Boards are non-reactively coupled and optimized for symmetrical multiprocessing and redundant systems.
Board and backplane dimensions, front panels, and hot-plug mechanisms for CPCI-S.0 are identical to and fully compliant with PICMG 2.0. The specification is also compatible to IEEE 1101 and can accommodate standard 19-inch racks. This guarantees that mezzanine modules that have been designed for these boards – and which are indirectly based on the IEC1101 standard – are also compatible with the CompactPCI Serial standard.
Unlike the modified connector configuration used in CompactPCI PlusIO, the CPCI-S.0 connector is an entirely new design supporting more pins capable of operating at higher frequencies.
This enables higher signal density and supports transmission frequencies of 12 Gbs/second. Also, contrary to CompactPCI and CompactPCI PlusIO, the male-pin plug is mounted on the module and the female receptacle is on the backplane, as it is in VMEbus systems.
This arrangement is a more rugged construction than legacy CompactPCI and eliminates the concern of twisted pins on the backplane. In the event that a connector pin does fail, the plug-in card can be replaced instead of the whole system backplane. The new CompactPCI Serial connector design is also better prepared for harsh environments, with walls on all four sides.
Depending on the function of the board, there are a number of ways those connectors might be assembled. For example, a peripheral board in 3U format equipped with only one connector at the backplane can save costs.
However, using multiple modular connectors positioned next to each other on a larger board can not provide the same rigidity as a single larger connector that would help to stabilize the board mechanically. For CompactPCI Serial’s use in rugged applications, an additional element has been introduced – the guide element – for guiding, holding and stabilizing the plug-in card on the backplane.
This way, a 3U assembly is also guided in the middle of the backplane, even when only the lowest connector is assembled. With the guide element, shock and vibration resistance are improved because the PCB cannot bend.
An ancillary benefit of CompactPCI Serial lies in the potential for hot-swapping peripheral boards during operation without damaging them and without disturbing the function of the computer.
The ability to accomplish this with several simple measures in a 19” system complying with IEC 1101 offers advantages for multiple real-world circumstances such as a pluggable hard disk, RAID systems or complex multiple systems.
One concept, two standards, multiple interfaces
With their dedication to enhancing the CompactPCI concept without rendering it obsolete, both the CompactPCI PlusIO and CompactPCI Serial standards accommodate the use of previously designed CompactPCI peripheral boards in upgraded applications.
While the CompactPCI Serial slots are best suited for functions like 10 Gigabit Ethernet or high-end graphics with high data-rate requirements, the parallel CompactPCI bus still delivers acceptable performance for many types of conventional I/O such as binary or analog signals. This best-of-both-worlds scenario is a rare commodity in the rapid-turnover world of computing technology.
It provides CompactPCI users with a migration path that helps them maintain the value of past equipment investments by opening up new avenues to high-speed communications capabilities that could extend the practical life of existing systems investments by up to 15 years.
Since 1992, Barbara Schmitz has served as Chief Marketing Officer of MEN Mikro Elektronik. She graduated from the University of Erlangen-Nürnberg. Later, she studied business economics in a correspondence course at the Bad Harzburg business school and followed an apprenticeship in Marketing and Communications in Nuremberg.
Loading comments... Write a comment