Design Of Solid-state Storage System Based On Zynq

Radar signal measurement system is mainly used in the engineering application to determine whether radar signal meets the needs.FPGA is only used to design AD sampling module and PCIe interface module in the traditional radar signal measurement system.The sample data will be send to the PC for processing and storing through the PCIe interface.However the traditional processor is slow in processing a large number of real-time signals.but the FPGA characteristics of parallel data processing,FPGA is more suitable for real-time system.At this time,the every modules in the radar measurement system are designed based on FPGA is a suitable choice.Different from the design of storage module in traditional system,we should design an embedded storage system to store radar signals in the system storage module.The embedded storage system based on Xilinx Zynq platform mostly divides the system design into two parts.The storage interface is designed in the PL part of Zynq.The storage driver software is designed in the PS part by the form of standalone.However,the existing embedded storage system is developed in PS part by the form of standalone.It doesn't support file system,which can not directly manage the data in storage.And there is no data interface for radar system in system structure.As a new type storage,Solid State Disk mainly uses flash memory as storage medium.Optimizing the performance of embedded storage systems by improving the performance of solid-state disks is a reasonable option.To reduce the number of flash read and write and improve the hit rate of access are important ways to improve the performance of Solid State Disk.A common method is to study the buffer management algorithm.The principle of LLRU selecting the expulsion page will cause the cold clean page linked list of the algorithm to be empty after running for a period of time,the newly read cold page in buffer will be selected as the expulsion page immediately.This will cause the hit rate of the algorithm decreased significantly.And the LLRU algorithm does not discriminate between expulsion pages from the hot area and the cold area,which also leads to a decrease in the algorithm hit rate and unnecessarily read and write flash memory.Based on the above analysis,the embedded solid storage system is designed based on Zynq 7035 in this paper.Firstly,the PCIe interface and data interface are designed in PL part.Radar data is entered into the system by the data interface and stored in Solid State Disk through the PCIe interface.Then the data will be stored by the system though developing and transplanting driver software,and the data in the storage will be directly managed though transplanting Linux filesystem.The storage system can store the external data stream into Solid State Disk by validation.Then a multiple linked lists buffer management algorithm AM-LRU is proposed in this paper,which puts the pages in the buffer into four LRU linked lists,every linked list story the same type page.When the data in buffer is replaced,the cost function is used to select the page with the minimum replacement cost.By limiting the minimum length of the cold clean page linked list,AM-LRU avoids the problem that cold pages are difficult to be hot pages.And the hit rate of AM-LRU is increased as much as possible by using a secondary opportunity replacement strategy for the expulsion pages from the hot area.Finally,this paper simulates several LRU algorithms on the Flash-DBsim platform,and verifies that performance of AM-LRU algorithm is better than that of LLRU algorithm.