Dual dynamic random (DDR) access memory interface design for aerospace printed circuit boards

A radiation-hardened single board computer system for operation in a space environment, the radiation-hardened single board computer system comprising:

• a printed circuit board having a top side and a bottom side, said printed circuit board including a plurality of layers arranged symmetrically in a two-halves configuration above and below a central plane of said printed circuit board, said printed circuit board including:
• a first radiation tolerant field programmable gate array (FPGA) processor device disposed on said top side and a second radiation tolerant FPGA disposed on said bottom side of said printed circuit board,
• four radiation tolerant dual double data rate synchronous dynamic random-access memories (DDR2 SDRAMs) disposed on said top side of said printed circuit board and
• four DDR2 SDRAMs disposed on said bottom side of said printed circuit board and mirroring said four DDR2 SDRAMs disposed on said top side, wherein said four DDR2 SDRAMs on said top side and said four DDR2 SDRAMs disposed on said bottom side of said printed circuit board store an operating system and dynamic application data, and
• a plurality of peripheral components mounted on said top side and said bottom side,
• wherein a layout stack-up of said top side of said printed circuit board comprises:
• a first ground layer;
• a first signal layer disposed on said first ground layer;
• a second ground layer disposed on said first signal layer;
• a second signal layer disposed on said second ground layer;
• a third ground layer disposed on said second signal layer;
• a third signal layer disposed on said third ground layer;
• a fourth ground layer disposed on said third signal layer;
• a first power layer disposed on said fourth ground layer;
• a second power layer disposed on said first power layer;
• a fifth ground layer disposed on said second power layer;
• and
• a top layer disposed on said fifth ground layer.