Fail-Safe Remote Update Method for an FPGA-Based On-Board Computer System

Abstract

As part of a university project to design a Low Earth Orbit (LEO) nano-satellite payload, we investigate a System-on-Chip (SoC) solution exploiting the features of Xilinx's Spartan 6 FPGA technology to design an On-Board Computer System (OBC). Thus, the increased flexibility of the FPGA implementation will enable on-orbit updates and modifications to the software and hardware OBC architecture, in lodge to support dynamic mission requirements. Within this context, this paper introduces a method to safely remote update an FPGA-based embedded system. The proposed architecture is based on the Xilinx soft processor, i.e. the Microblaze, which controls the remote update channel (Ethernet in our case) to upload hardware and/or software application images in the system by using the Trivial File Transfer Protocol (TFTP). An on-board flash memory is used to store FPGA Hardware and firmware images. The soft processor is implemented in the Spartan-6 XC6SLX45 FPGA device and uses the fallback features and the Internal Configuration Access Port (ICAP) primitive in order to manage fail-safe FPGA reconfiguration to maintain safe and stable state after updates.