As an extension of the parallel CompactPCI standard PICMG 2.0, a CPU board which is developed according to the serial CompactPCI PlusIO standard PICMG 2.30 can also be used as a system slot in a hybrid system. Such a hybrid system can offer CompactPCI slots as well as CompactPCI Express and CompactPCI Serial slots. (It can even be combined with other bus-based slots like VME).

PICMG 2.30 is downward-compatible to PICMG 2.0 without any limitations because it just fixes the J2 pin assignment for:

• 4 x PCI Express (one lane each)
• 2 x Ethernet 1000BaseT
• 4 x USB 2.0
• 4 x SATA/SAS

At the same time it introduces a new 100% compatible 2-mm-connector, which is also suited for transmission of high frequencies. The parallel PCI bus is not changed but is limited to a data bus width of 32 bit. PICMG 2.30 can be used for both single and double Eurocard formats.

Hybrid systems offer the possibility to integrate boards with serial interconnects beside the parallel bus-based boards – an easy and cost-saving way to migrate to modern technologies.