Research On Storage Management And Error Control Technology Of Solid-state Disk

With the development of modern technology, the pattern of operations will also be significantly changed in the future. While more high-tech weapons appear, the electromagnetic environment of battlefield becomes more and more complex, ever-changing combat situation. The data produced during information-based operations and trainings increases by geometric series, so the fast exchange and transmission for a large number of information and data become urgently in need. With the development of information technology weapon, hard disk, as an information exchange and data storage carrier, plays a very important role. Traditional mechanical hard disks show many disadvantages for example bad anti-seism capability,limited temperature range , not fit for wet environment and low performance.so,in the industry,especially in military industry,It is ideal for SSD applications.Aim to the special requirements of storage strategy asked by modern military field, this paper proposes a Solid-State Disk. In this system, we use FPGA as a control chip and NAND Flash memory as storage media, no mechanical devices, good anti-seism capability, wide temperature range, no noise, reliable and energy-saving,It is one effective solution for data storage in the current military field.The main research contents are as follows: (1) Describes the significance of this research, and introduces the key technologies of SSD, and their development status, the main work; (2) The storage management technology. Study the address mapping technology, the page-level, block-level and mixed-level address mapping; Because there are erasing bad blocks and inherent bad blocks in the NAND Flash, On Garbage Collection algrorithmic,this paper proposes an improved GCbTL algorithm. The study show improved GCbTL can achieve garbage collection effectively; Considering the wear problem caused by erase operation of NAND Flash block before writing data, this paper analyses Dual-Pool algorithm. Thinking of the low I/O efficiency of Dual-Pool algorithm, we propose an improved Dual-Pool algorithm. The test proves that the improved algorithm don't reduce obviously the wear leveling, and raises the flash memory I/O performance; (3) Because the traditional ECC using Hamming code method only can detect two errors, and correct one error, can't satisfy the requirements in military field. The design uses BCH (4200,4096,8) code, and can achieve 8-bit errors correction, greatly improving the reliability of data transmission; (4) hardware design of SSD. Finish the SATA protocol logic module and NAND Flash memory management module, complete the function of SSD systems.