The Development Of A Fiscal Cash Registers

Fiscal cash register is a cash register with the fiscal function. It should ensure the correct production and the reliable storage and the safe transfer of the business data. To reduce and prevent the tax loss is the main purpose of using fiscal cash register. Because of the scarcity of the functions and the safty and the reliability and the expandibility of the present fiscal cash register, I advance the subject to develop this fiscal cash register.The fiscal cash is designed according to the Chinses Criterion of fiscal cash register. It is based on fiscal IC card. The fiscal cash register produces the fiscal data by the fiscal card and storage the fiscal data in the fiscal card and the fiscal memory and transfers the fiscal data to the Revenue through the user card.I adopt the idea of stratification and modularization in my design. The fiscal cash register is devided to three stratums from bottom to top. They are the hardware, the bottom software and the top software. Every stratum is devided into modules. A module accomplishes a certain function. This idea makes modules and stratums independent. It makes convinent in maintenance and advancement and expansion.R8830, a 16-bit MCU is used as the only one processor in this design. I select SST28SF040, a EEPROM with the function of data protection to storage my software. K9F2808, a Nand_Flash memory with the bad block mapped function is used as a fiscal and invoice memory. Using a CPLD in design promotes the facility and secrecy of thehardware. I advance the durability of printer through optimizing the printer drive circuit.The build-in software is made of the bottom software and the top software. The fiscal cash register boots at first though the bottom software after power on, and then run main( ) in the top software, waiting for keyboard to be pressed. Every function is driven by the keyboard (or the mode switch) and the LCD displays the relevant menu, and then the fiscal cash register actualizes man-mechine alternation. The fiscal cash register runs the certain module in the top software, accomplishes certain function. The top software will call the certain module in the bottom software to drive the hardware to accomplish the fuction process with the-bottom software together. After these finished, the fiscal cash register turns to main( ).The fiscal cash register is a jural register with the function of tax. The fiscal cash register' s information security is every important. I study the Chinese criterion of { Information technology—Security techniques—Evaluation criteria for IT security)) and bring forward the security funcitonal requirements of the fiscal cash register and design the fiscal cash register according to these requirements.