CPCI Serial Space is based on CompactPCI® Serial. However, some unnecessary features were removed. For example, CPCI Serial Space does not need to route USB or SATA signals over the backplane so these signal lines can now be used for additional rear I/O connections. On the other hand, due to the requirements of some space applications, CPCI Serial Space requires in comparison to CompactPCI Serial new signal lines.
CPCI Serial Space does not route USB or SATA links on the backplane. These signals can be used for rear I/O connections.
CompactPCI Serial defines dedicated PCI Express and Ethernet links on the backplane. CPCI Serial Space maintains the routing of these signal lines but defines these backplane links as physical connections not dedicated especially to Ethernet or PCI Express. This has the advantage that they can be used for Ethernet and PCI Express links but also for other transport protocols like SpaceWire, TTEthernet and EtherSpace for inter-board communication.
Like in CompactPCI® Serial, a full mesh network on the backplane is supported. All slots can have a connection to the full mesh network – a point-to-point connection from each slot to all other slots.
A CompactPCI® Serial backplane routes PCI Express as a single star (the system slot is the center of the star). CPCI Serial Space backplane routing is compatible with that and additionally supports a second system slot. The dual star architecture improves the reliability and flexibility of the system. So all peripheral slots can have a serial connection to system slot A. This complies with the CompactPCI® Serial base specification.
Peripheral slot 8 is extended to be system slot B, the second system slot. System slot B is identical to system slot A. It can be used as an additional system slot, but it can also be used as a peripheral slot (per. slot 8). However, each peripheral slot has a connection to system slot A and additionally a second serial connection to system slot B.
A shelf controller can control the power supply of all boards separately. Also the shelf controller can check the status of the boards and can reset the boards individually. Two redundant CAN busses are available additionally as board management busses. Neither the shelf controller connector nor the shelf controller itself is specified in this specification.
The mechanical design of CPCI Serial Space is fully compatible with CompactPCI® Serial. However, the board to board pitch is 5HP (= 25,4 mm) only – for air cooled as well as for conduction cooled systems.
