Hardware System Design Of Encryption Card Based On MPC8315E And PCI-E Interface

Nowadays the secure transmission of information on network has gradually become the focus of attention, and encryption technology is the effective means to solve the security problem. The encryption technology is mainly divided into two kinds, which are software encryption and hardware encryption. Software encryption has disadvantages of consuming a large amount of system resource because of CPU's participation all the time, low speed and easily being decrypted. Yet, the hardware encryption has characteristics of high speed, high security and so on. The hardware encryption is widely used in the form of encryption card, and encrypt card has low cost, high performance characteristics. Therefore, it is of great significance to develop the hardware encryption card.The subject puts forward a system design solution of encryption card hardware based on PowerPC platform and PCI Express (PCI-E for short) bus. The encryption card uses MPC8315E processor chip as the main processor, which is belong to the series of the PowerPC produced by Freescale Semiconductor Inc. The chip has rich interfaces, and the main work of this thesis is designing the whole hardware circuit system of encryption card based on these interfaces. The circuit design includes PCI-E bus interface circuit, DDR2memory circuit, Nor Flash interface circuit, Nand Flash interface circuit, extension module of encryption interface circuit, UART interface circuit, JTAG interface circuit, temperature detection module circuit, sequential matching circuit, clock circuit, reset circuit and power management circuit. The circuit design mainly focuses on PCI-E bus interface circuit, DDR2memory interface circuit, Nor Flash interface circuit, Nand Flash interface circuit and power management circuit. Because PCI-E and DDR2work in high frequency, the signals of which belong to high frequency signals, and the performance of PCI-E and DDR2influences the whole system very much. Since the routing and simulation for high frequence signals impacts directly on the signal integrity and the electromagnetic compatibility of the system, the other emphasis and difficulty of the paper is routing and simulation for high-frequence signals. Routing and simulation of DDR2are carried on particularly in this paper. The work of routing is setting routing rules, which includes differential pair, line width, line spacing, isometricly matching and so on. Simulation analysis contains the reflection of high-speed signal transmission line, crosstalk, timing etc. The paper puts forward the effective methods of reducing reflection and crosstalk, and determines the matching rules of transmission line length to meet timing.The preliminary debugging of the encryption has finished, and now the comprehensive debugging of the card is going on. In the end, the main processor MPC8315E controls the encryption card to work, and MPC8315E and extension module of encryption are responsible for data encryption and decryption. The encryption card communicates with PC or industrial control computer by PCI-E interface.