Design Of Network Storage Cascade Controller On The Basis Of PM8005+FPGA

With the advent of the era of cloud computing, IT system requirement for data storage system is more and more high, not only requires storage system to have a large capacity, both also demands to ensure data security. Data storage system is the foundation of the whole IT system, and the foundation of the IT technology relies for existence and development platform. Traditional computer storage system is a storage device (usually disk) and application server hardware directly installed on the same chassis, and the storage device is for the application servers used independently alone. Obviously, in the era of cloud the forms of traditional single hard disk to store today has been difficult to meet the needs of users. At present, various types of network storage cascade controller at home and abroad, this paper comparing the advantages and disadvantages of network storage cascade controller at home and abroad and the development trend of a cascade controller, combining previous research achievements in the field of network storage, designs a cascade controller based on PM8OO5+ FPGA.The products of the current domestic research and development of the network storage cascade controller are generally in the form of a single bus interface disk extension, and that are not compatible with various types of existing disks, the applicability of the system is not high, and in anti-risk ability is weak. This paper describes network storage cascade controller is a grasp of the weakness of existing products, using SAS interface extension PM8005 and timing management chip FPGA to constitute the main body of this system architecture, the idea of modular design, put forward the compatible design scheme of double power input and double clock input, designed IC bus IP core which can be widely transplants using in the field of network storage, through the design of this system improved the applicability of the cascade controller effectively, enhanced ability to resist risks.This paper firstly introduces the development background of the network storage cascade controller products, and elaborates the research status at home and abroad in the field. In a mature way under the guidance of the principle, starts the actual research and development of this system. The design of network storage cascade controller on the basis of PM8005+FPGA are mainly by changing the PM8005 internal register values and up and down through the SAS bus transmission control information to achieve the purpose of control the storage network system. After more than one year’s research,here are the achievements:(1)The completion of cascade extension bus driving interface module based on SAS 2.0 protocol. The cascade extension interface unit is designed based on SAS interface of hard disk, the interface extension unit mainly consists of SAS interface extended chip PM8005, through PM8005 extends out of 25 phy SAS hard disk interface. SAS interface is compatible with SATA hard disk, and through external software can be installed three bus transmission rate:1.5 Gb/s,3.0 Gb/s,6.0 Gb/s, the three kinds of the rate of high speed signal transmission, this system can guarantee that the integrity of the signal.(2) The completion of a real-time monitoring system based on the IIC bus module. This system of cascade plates respectively use two temperature sensors to monitor the temperature of air in inlet and outlet, with a piece of voltage detection chip to gather real-time voltage in the system. Through to the system of temperature and voltage monitoring to ensure that the coupling controller at the corresponding level safety and efficient operation for a long time.(3)The completion of the power management module which can be the compatible of two external power and has slow start function. According to the using habit of network storage products, the power management of this system is designed to be compatible with external 12V and 5V, and according to the characteristics of needing hot plug in this system,designs the function of power soft start,which can very good inhibit the strong surge current caused by hot plug, and increase the ability to resist risk of the system.(4)The completion of the IIC bus IP core based on FPGA. This system according to the characteristics of network storage products designed the IIC bus IP core, to control the system communication and related components, which has strong portability.To sum up,the design of network storage cascade controller on the basis of PM8005+FPGA has the function of application in the field of network storage, of course, this controller in such aspects as disk extension number also has the very big improvement space.