Design And Realization Of Encryption Storage Adapter Based On USB2.0 Interface

As the quickly development of computer technology, the daily office work model moves towards non-paper one, and the informationalization develops faster and faster. Information transformation and exchange change from the traditional paper documents to digital information. The storage device is various, early the main storage devices were diskette, 5-inch hard disk, now the disk, USB disk, CF card, small model pocket disk are very common. As the capacity of pocket disk is larger and larger, the volume is smaller and smaller, which makes information storage more convenient, meanwhile threatens the information security, especially in some special organization, like Public Security Office or Security organ, which have much more confidential information, therefore, it would be a great loss if the storage device contained confidential information broke down. According to this feature of Public Security Office, and meet the demand of public security work, I designed and realized an encryption device for external computer hard disc and hardware of CF card.This device is for USB2.0 interface. USB(Universal Serial Bus)is the external bus line of PC. Because advantages of fast speed, low cost, simple usage, plug and play support, easy to extent,etc. now is widely applied in all kinds of computer devices. Especially when the standards of USB2.0 came out, it became the main interface between Personal Computer and outer information transition, and the storage device with USB2.0 is also very common. This thesis introduced the standard and protocol of USB2.0, which is the basis of understanding the designing process.This thesis also analyzed the IDE interface of storage device andFAT32 document system. IDE(Integrated Disk Electronics) is also called ATA bus line interface, which is a common interface of hard disk drive. IDE hard disk has a larger capacity, a higher performance-price ratio, it is the mainstream device commonly applied now. FAT32 document system is the highest version of Microsoft FAT document systems, and the most common used hard disk document system in the WINDOWS system, this design adopted this document system.The encryption used in this design is hard-encrypt. Hard-encrypt is through combining hardware and software to realize the encryption of data. Compared with traditional encryption of software, hard-encrypt has two features: high intensity in anti-encryption, and good in stability and compatibility.This thesis is for designing system hardware and firm ware. USB2.0 interface chip CY7C68013 of Cypress company is the core part of hardware. CY7C68013 is of FX2 product line of Cypress company, and also the first line of USB2.0 chip of Cypress. CY7C68013 is a single slice machine with a strengthened MCS51 core and USB interface, which is completely in accordance with USB2.0 protocol and can provide 480Mbps transfer rate. It also provides two serial ports externally, which can transfer information very conveniently; RAM of 16KB within the chip can sufficiently meet the demand of data transformation every time, so there is no need for line out RAM. Centering on CY7C68013, this paper designed the outline of hardware, further to partly design in detail of power supply, power-clock reset circuit, reset circuit and fixed storage circuit, etc. then complete the design of hardware theory outline. Based on the theory outline, PCB circuit board and assembly parts are designed and testing sample machine is made.Firmware development is the key of this design. CY7C68013 chip has two cores, one is USB Serial Interface Engine(SIE), the other is 8051 core. The firmware development is divided into three phrases. The first phrase is recording the mon-int-sio1.hex into the chip by using the supervision program EZ-USB Control Pane provided by Cypress, then starts the UART1 as the debugging serial post. The second is to use software Keil uVision2 to program code and debug, use debugging serial port while debugging. The third is to write the final debugged and correct program code into EEPROM and run in the RAM by EEPROM when starts device.The last is to test the finished device sample machine. The testing result shows the hardware disk of connecting encryption adaptor can be used as the normal one, but without the encryption adaptor it can't work and it is prompted to be reformatted. Through the testing, the function of the adaptor is realized.Through doing research on the relative theory and technology, this thesis designed and realized a encryption storage adaptor based on USB2.0 interface. This adaptor has already realized the basic functions and explained the feasibility, meanwhile provided some thoughts for the demand of relative industry. Because the sample machine is still in the testing period, we need point out, there are still many places to improve, we need do more work if apply it into practice.