The HiRel/CanSat interconnect boards hold the other boards on the top and the bottom sides.
|V1.0||CanSat Interconnect v1.0 Schematic PDF|
The FPGA board connects to every other board, as shown below:
The bottom interconnect board provides the 3.3 V power supply. The top board provides the 5 V. Both interconnect boards provide 4 lines from the FPGA board to each slave boards.
On the interconnect board, both rows of the 12-pin slave connectors carry the same signals. 6-pin connectors could have been used, but the 12-pin connectors provide a better mechanical stability.