Application-Specific Backplane Architectures with CompactPCI® Serial

Version 1

    Author: Manfred Schmitz, CTO MEN Mikro Elektronik


    CompactPCI Serial supports every interface defined in the specification on every backplane slot, i.e. Ethernet, PCI Express, SATA and USB (USB 2.0 and USB 3.0). This is very convenient, easy to understand and easy to handle.


    For certain applications with lot sizes of more than 50 systems, a customer-specific backplane might be recommendable. On this backplane, specified interfaces can be wired to specified slots. Theoretically, such a backplane might have 8 slots only for Ethernet, 8 slots only for PCI Express, 8 slots only for USB and 8 slots only for SATA beside the system slot (i.e. a total of 33 slots). No switches or bridges are needed for this either, but now the peripheral boards can only be plugged into predefined slots.


    The architecture of CompactPCI Serial, PICMG CPCI-S.0 is based on one system slot and up to eight peripheral slots. The CompactPCI Serial backplane is completely passive - no switch or bridge boards are needed. Each peripheral slot is identical, i.e. every peripheral board can be plugged into every slot, without any kind of configuration. That's what users of CompactPCI (parallel) are used to, and this user-friendly concept has been transferred to CompactPCI Serial.


    A good example for such a backplane would be one where at least the SATA slots are separated from the other interfaces. This would result in 8 peripheral slots which support Ethernet, PCI Express and USB and 8 additional slots which can only accommodate SATA boards (hard disks). Such a modular computer would have eight slots for typical peripheral functions and 8 slots for a RAID system, i.e. a total of 17 slots including the system slot.


    This example shows how cost-effective and technically optimal solutions can be found based on CompactPCI Serial. The CompactPCI Serial standard makes modern technology simple, robust, flexible and inexpensive - while the mechanics remain 100% compatible with CompactPCI 2.0.