Research On Solid-State Storage Technology For Integrated Electronic System On Satellite

Solid-state storage system can achieve the data processing,data storage and other functions as a key component of the integrated electronic system on satellite.With the complex and diverse development of space missions,solid-state storage systems are facing the following two issues: On the one hand,the current design of solid-state storage system is highly customizable,poor flexibility and the scope of application is limited,at the same time,the function of plug-and-play can not be implemented;On the other hand,because of the strictly limit of the high-performance aerospace and military-grade electronic components for China’s exports,and the domestic design level of the core,high-end and basic components is low,the problems above-mentioned led to the low performance of the domestic solid-state storage system on satellite.In this context,making the technology of FPGA-based solid-state storage as a starting point and combining with applications of solid-state storage in the integrated electronic system,following research works have been completed in the generalization,integration and high reliability,etc:Firstly,the design scheme of the solid-state storage controller ASIC is proposed.It can complete the function of reception of high-speed,multi-parallel and large data from spacecraft loads,efficient control of high-capacity NAND Flash storage media and data transmission according to CCSDS AOS protocol.In order to improve the efficiency of data transmission,the improved polling arbitration mechanism and multi-channel caching technology based on tense are adopted in the virtual channel scheduling mechanism.For scalability and versatility,the universal 1553 B bus and SpaceWire bus interface are used.In the applications of system-level,ASIC achieve the standardization of storage boards and plug and play capabilities as the core of system,and it will accomplish the replacement of FPGA devices in the storage systems in the future.Secondly,a design of IP core used as solid-state storage controller is proposed with the aims of upgrading the next generation of anti-radiation Loongson processor SoC and expanding the application of NAND Flash storage media.It has the ability to refresh and reload control of SRAM-type FPGA while achieving the normal function of data storage.all the space in the storage medium can be read and writed by computer by the use of internal timing conversion,which able to complete the function of update the FPGA configuration file in-orbit.Also can it play a replacement for NOR Flash or E2 PROM by using of NAND Flash.At last,the large capacity data storage devices of spacecraft mainly adopt the solid-state storage based on NAND Flash chip.However,due to data bit error caused by the single event upset(SEU)of the space environment and the threshold voltage deviation during memory operation,the data reliability of the storage device is reduced.According to the physical structure and data structure of the NAND Flash chip,an error detection and correction(EDAC)coding design with RS(256,252)+LDPC(8192,7154)cascade encoder circuit is proposed,for improving the error tolerance of data storage devices.Moreover,the method for circuit realizing of the coding algorithm is optimized.The overall design can improve the data storage system reliability,with the limited hardware resources overhead.