Design And Implementation Of A Fiscal Cash Register Based On Embedded System

The embedded system is a specific computer system for a specific purpose. It continually gets high achievements through the process to meet the industrial applications' requirements of better performance and functionality. With the development of embedded system, the 8 bit and 16 bit MCUs will be unsuitable for complex applications. The price of a 32 bit MCU is now equal to that of an advanced 8 bit MCU owing to semiconductor technology's innovation. A 32 bit MCU with rich peripherals on chip has a high rate of performance/price, so more and more 32 bit MCU will be used in embedded system.A Fiscal Cash Register (FCR) is intended to control taxes, it is a typical embedded system. FCR will be widely used in trade, restaurants, service fields and amusement places. According to the initial statistics of taxpayers, at least 10 million FCRs will be needed. A national standard GB18240 has been made for FCR to define the general specifications, test methods and inspection regulations.The FCR which we have developed conforms to the GB standard. It has high performance and low cost, because it adopts the method of "S3C44B0X CPU + software" to implement the main peripherals. This dissertation discusses the design and implementation of a FCR based on embedded system. In hardware part, it describes the EDA tools and the PCB design guide and analyzes the main module circuit such as Ethernet module, IC card reader module and micro printer drivermodule; in PCB design process, it uses EMC and SI simulation technique. In software part, it introduces the development environment, software architecture and uClinux; then it details the implementation of the main device drivers such as LCD and I2C under |j.Clinux; and then it introduces an approach to protect the data, analyzes the mechanism of the implementation of YAFFS, and completes the porting of the file system, it also discusses how to handle the system when power is off illegally; at last it introduces FCR's application software. At the end of this dissertation, it summarizes the whole design and implementation and gives some suggestions about the further improvement.