Radiation Hard Monolithic SDRAM to Support DDR2 and DDR3 Architectures

Space Micro has developed the architecture for a radiation hardened memory subsystem that targets DDR3-and-beyond generations of DRAM. The architecture combines server platform error correction and memory buffer-on-board schemes with Space Micro proprietary techniques for radiation hardening and size, weight, and power reduction. During the NASA Phase I effort, Space Micro demonstrated two key elements of the architecture: (1) a scalable error correction coding (ECC) scheme that optimizes the robustness vs. efficiency vs. chip count tradespace, and (2) a Rad Hard By Design (RHBD) timing circuit for advanced DRAM fly-by routing. Space Micro has developed a Phase II plan for developing a server platform-like bridge chip that integrates ECC, interface logic, and timing circuitry into a high performance, low size, weight, and power (SWaP) memory subsystem suitable for next generation spacecraft computing.