Chaotic digital cryptosystem using serial peripheral interface protocol and its ds PIC implementation

The current massive use of digital communications demands a secure link by using an embedded system（ES） with data encryption at the protocol level. The serial peripheral interface（SPI） protocol is commonly used by manufacturers of ESs and integrated circuits for applications in areas such as wired and wireless communications. We present the design and experimental implementation of a chaotic encryption and decryption algorithm applied to the SPI communication protocol. The design of the chaotic encryption algorithm along with its counterpart in the decryption is based on the chaotic Hénon map and two methods for blur and permute（in combination with DNA sequences）. The SPI protocol is configured in 16 bits to synchronize a transmitter and a receiver considering a symmetric key. Results are experimentally proved using two low-cost dsPIC microcontrollers as ESs. The SPI digital-to-analog converter is used to process, acquire, and reconstruct confidential messages based on its properties for digital signal processing. Finally, security of the cryptogram is proved by a statistical test. The digital processing capacity of the algorithm is validated by dsPIC microcontrollers.

Design of IP core based on AMBA bus

With the rapid development of integrated circuit(IC)technology,reusable intelligent property(IP)core design is widely valued by the industry.Based on the in-depth study of the functional characteristics of advanced microcontroller bus architecture(AMBA),a design scheme of IP core is presented,and it is divided into the functional modules,and the structural design of the IP core is completed.The relationship between the internal modules of the IP core is clarified,and the top-down design method is used to build the internal architecture of the IP core.The IP core interface module,register module,baud rate module,transmit module,receive module,and interrupt module are designed in detail by using Verilog language.The simulation results show that the designed IP core supports serial peripheral interface(SPI)protocol,the function coverage of IP core reaches 100%,the maximum working frequency reaches 200 MHz,and the resource occupancy rate is less than 15%.The reusable IP core can support multiple data formats,multiple timing transmission modes,and master/slave operation modes,reducing the resource consumption of hardware circuits and having stronger applicability.

Intelligent Control System of Textile Mill's Air-conditioning

This paper briefly analyzes the present situation of textile mill＇s air-conditioning system. Since it is difficult to establish detailed math model to control a textile mill＇s airconditioning system because of the influence of various factors such as the differences in seasons, regions, etc., most air-conditioning equipment can not be controlled automatically. This paper suggests utilizing multi-function data acquisRion card to collect the data about the temperature and humidity of a workshop, processing the data on a PC, comparing them with the expert database, and then using the 485 serial port expanding module to output the parameters, which are used to control the inverter, so that the purpose of adjusting the temperature and humidity of the workshop is achieved.