Terran Orbital is excited to offer a
computer system that delivers tolerance to ionizing radiation in
static random-access memory (SRAM)-based field-programmable gate
array (FPGA) through a novel fault mitigation strategy. This novel
computer system achieves radiation tolerance through a new
architecture that can detect, avoid, and repair faults caused by
high energy ionizing radiation by exploiting the re-programmability
of commercial off-the-shelf (COTS) FPGA combined with an external
spatial radiation sensor for environmental awareness.
A many-core computer architecture has been combined with fault detection and recovery using partial reconfiguration of an FPGA for localized repair. The FPGA fabric is partitioned into tiles which contain homogenous soft processors. At any given time, three processors are configured in triple modulo redundancy (TMR) to detect faults. Spare processors are brought online to replace faulted tiles in real time. A recovery procedure involving partial reconfiguration is used to repair faulted tiles. This type of approach has the advantage of recovering from faults in both the circuit fabric and the configuration RAM of an FPGA in addition to spatially avoiding permanently damaged regions of the chip.
An external radiation sensor for environmental awareness was fabricated at the Montana Micro-fabrication Facility at Montana State University. This sensor is coupled with the FPGA to reduce the latency between a fault occurrence and repair by the scrubber. The overall size of the sensor is 20 × 20 mm, making it large enough to cover any commercially available FPGA die. The sensor was designed with 16 channels on each side to give a total of 256 discrete detection pixels. A 300-μm-thick intrinsic silicon wafer was used as the base material for fabrication. The sensor system was designed for modularity for ease of testing. The sensor was packaged on its own PCB, while the 32 channels of amplifier electronics were implemented on a separate 100 × 100 mm PCB into which the sensor was plugged.
Computer System Stack