Research On See Vulnerability Analytical Approach Of Spaceborne SRAM-based FPGA Circuit

In recent years,the requirement of spacecraft is becoming more and more complex,while the development of radiation hardened integrated circuit is relatively backward.In order to meet the demand,SRAM-based FPGA has been widely used in spacecraft because of its advantages of reconfigurable and high cost performance.However,proton and heavy ions in the space radiation environment can cause the single event effect.After the occurrence of a single event upset in FPGA circuit configuration bit,the SEU will be propagated and coupled in the circuit function module,and ultimately leads to the function failure of the circuit.FPGA circuit SEE vulnerability is the probability model of the SEE caused by single particle,and the probability model of function failure induced by SEE.Space practice shows that single event effect has become an important reason for the failure of the spacecraft.Therefore,it is an urgent problem to estimate the SEE vulnerability parameter in the early design stage of FPGA circuit,which will provide quantitative basis for anti SEU reinforcement design and evaluation.This leads to the basic problem of this paper-how to accurately and efficiently to estimate the SEE vulnerability parameter of the spaceborne FPGA circuit.Around this basic problem,four key technical problems have been studied as following:1.On orbit SEU rate estimation.The physical meaning of SEU rate is the probability of single particle upset per unit time,and it is determined by the single particle upset cross section curve and space single particle flux spectrum.Single particle flux in the traditional spectrum analysis rely on historical data for a satellite borne particle detector,is a kind of static analysis,how to construct a dynamic analysis method,and more accurately estimate the SEU rate of FPGA is worthy of study.Therefore,the estimation of single particle upset rate on the FPGA orbit is the key problem in the single particle vulnerability analysis of spaceborne FPGA circuits.2.SEE vulnerability bit analysis.SEE vulnerability bit which means that the change of configuration status will affect the function of the FPGA circuit,and the set of vulnerability points determines the output error rate of the FPGA circuit.For the configuration bit used in the FPGA circuit,it will cause the error of the output of the circuit,and the part of the configuration bit is not used,which will cause the error of the output of the circuit.These potential single particle vulnerability points are worth to be analyzed,and it is of great value to estimate the error rate of FPGA circuit.Therefore,the single particle vulnerability analysis problem of FPGA circuit is the key problem of the single particle vulnerability analysis of spaceborne FPGA circuit.3.Circuit function module coupling factor analysis.Complex FPGA circuit can be divided into a set of different function modules,SEE soft error propagation in the circuit,causing the error propagation and coupling effect between different modules in the circuit.In the early design stage of circuit,the coupling relationship between different circuit function modules is analyzed,which is helpful to understand the topology structure of different function modules in the circuit,and the coupling parameters can be used to guide the design of the circuit.So,the problem of the coupling degree analysis of FPGA circuit is the key problem of the single particle vulnerability analysis of the spaceborne FPGA circuit.4.SEE failure rate estimation.After the occurrence of a SEU in FPGA,in the circuit function module of communication and coupling,only to the output side of the circuit function will have an impact.In order to calculate the function error rate of the FPGA circuit caused by single particle,the advanced method is needed to be adopted to model and analyze the error of the FPGA circuit caused by single event upset.Therefore,the single particle failure rate estimation problem is the key problem of the single particle vulnerability analysis of the FPGA circuit in the orbit of the FPGA.In order to solve the key technical problems mentioned above,this paper proposes an estimation method of single particle flux spectrum based on dynamic nonlinear filtering is proposed,and SEE vulnerability bit analysis method combined on configuration bit pre parsing and netlist of analysis is proposed,and a method based on the fault injection code level automatic coupling is proposed,and SEE failure rate estimation method based on cellular automaton is proposed.These methods can solve the corresponding four key technical problems,both through theoretical analysis and experimental verification,proved the validity and feasibility of the technology,provides the design basis for the research and development of spaceborne FPGA circuit.