Research On Key Technology Of Radiation-hardened Design And Evaluation Of SRAM-based FPGAs

With the increasing demands for complex space missions,the reliability requirements of satellite payloads for on-orbit electronic systems continue to increase,and the single event effect induced by charged particles in space has become the most important threat to the on-orbit operation of electronic devices.Static Random Access Memory（SRAM）-based Field Programmable Gate Arrays（FPGA）has been widely used in satellite payloads due to its high performance and reconfigurable characteristics.However,SRAM-based FPGAs are sensitive to space radiation effects,and effective radiation-hardened design technology must be adopted for them under the premise of limited on-board resources to ensure the stability of spacecraft on-orbit operation.This thesis focuses on the anti-irradiation technology of spaceborne SRAM-based FPGAs,studies the hardening design and evaluation method of SRAM-based FPGAs against single event upset,and relevant test verifications are carried out.The work and main innovations of the thesis are as follows:（1）According to the different functional units of SRAM-based FPGAs where single event effect occurs,the influence of single event effect on SRAM-based FPGAs is expounded from three aspects:the upset from the configuration data,the upset from the user logics,and the upset from the control units.Then,the performance of different radiation-hardened design methods has been compared and analyzed.It is pointed out that due to the dynamic change of data stored in Block Memory（BRAM）,the traditional scrubbing operation may affect the reading of real-time data and thus interrupt the normal working process of the FPGA.Therefore,the hardening of BRAM is the bottleneck of radiation-hardened design of spaceborne FPGAs currently.（2）Aiming at the problems of high resource consumption and access conflict in the traditional BRAM anti-irradiation hardening method,a BRAM anti-irradiation hardening design method based on time-sharing scrubbing and location constraints is proposed.On the one hand,this method monitors the idle state of the BRAM accessed by the internal algorithm,and realizes the self-scrubbing of the BRAM by means of time division multiplexing.On the other hand,by adding location constraints,the probability of BRAM data anomalies caused by single event upset is effectively reduced.The results of the radiation test show that after adopting the above-mentioned BRAM hardening design methods,the single event functional interruption cross section of a certain type of spaceborne FPGA designed by our laboratory decreases from 5.4×10^-4cm² to 9.92×10^-5cm²,a decrease of about 82%,and the reliability of the BRAM anti-irradiation hardening design has been greatly improved.（3）Since not all single event upset lead to the failure of system functionality,traditional evaluation index based on single event upset cross section may not be able to fully and accurately evaluate the reliability of hardening design of spaceborne SRAM-based FPGAs.In response to this problem,a classification standard based on the characteristics of FPGA resources and an evaluation index called classified configuration data abnormal rate are proposed.Different types of single event upset faults are classified and evaluated,and this evaluation method is verified by fault injection test using the XQR2V3000 FPGA device under the assumed geosynchronous orbit working scenario.The relevant research results in this thesis can be applied to the radiation-hardened design of satellite payloads and platforms.The proposed BRAM hardening design method contributes to improve the reliability of radiation-hardened design of spaceborne SRAM-based FPGAs.The proposed classification standard and evaluation method provide an effective reference for the selection of FPGA devices.The above work has great practical and engineering significance for improving reliability and life of spacecraft.