Wakefield, Mass. - PICMG has released the CompactPCI Express Specification (EXP.0) designed to bring PCI Express technology to the PICMG 2.0 CompactPCI form factor, while maintaining compatibility with the latter’s hardware and software.
The specification defines the connector, electrical, and mechanical requirements of 3U/6U System Boards, Peripheral Boards, Switch Boards, and Backplanes. Boards that are defined in the specification include System Boards, Type 1 Peripheral Boards, Type 2 Peripheral Boards, and Switch Boards.
Type 1 Peripheral Boards share the same pin definitions as System Boards, so a CPU board could be designed to work in both slot types. Type 2 Peripheral Boards, can be used in Type 1, Type 2, and Hybrid Slots. Switch Boards provide a modular way to provide PCI Express fan out.
The specification defines the system slot and board to have up to 24 lanes and up to four links of PCI Express for up to 6 Gigabytes/second system bandwidth per direction. Type 1 peripheral slots and boards can have up to 16 lanes of PCI Express for up to 4 Gigabytes/ second bandwidth per direction and Type 2 peripheral slots can have up to 8 lanes of PCI Express for up to 2 Gigabytes/ second bandwidth per direction.
According to Mark Wetzel of National Instruments, the EXP.0 subcommittee chair, more than 40 companies participated in the CompactPCI Express specification development process.
"CompactPCI Express leverages the Advanced Differential Fabric (ADF) connector used by AdvantedTCA to carry the PCI Express Signals,” said Wetzel. “The specification maintains hardware compatibility with CompactPCI by allowing backplanes to have CompactPCI slots as well as Hybrid Slots, which support CompactPCI, PXI, and Compact PCI Express peripheral boards."
Copies of the complete specification are available to PICMG members and can be purchased by non-members from PICMG. More information on new PICMG developments is available at www.picmg.org.