基于铁电存储器的POS机数据采集系统的研究

发布时间：2018-01-22 20:54

  本文关键词： POS机 数据采集器 ATmega128A FRAM　出处：《广西大学》2014年硕士论文　论文类型：学位论文

【摘要】：作为广泛应用于零售业的电子设备,POS机在日常消费生活中起着重要的作用。它给人们带来便利的同时,也使得相关部门对零售行业的监管变得更加困难。铁电存储器以其高速度写入、更高的读写耐久性和更低的功耗的特点,被广泛应用于各领域,并可以用来替换EEPROM和SRAM。综合以上特点,本文设计了一套以铁电存储器为存储单元,用于采集票据信息的POS机数据采集系统,主要研究工作如下：(1)系统研究了POS主机与票据打印机间的工作机理,通过比较分析SPP、EPP和ECP模式的工作时序,选取通用性较强的应答信号/ACK作为触发信号。(2)通过分析打印数据在并行总线上的传输特点,对数据进行缓冲和锁存处理,提高采集的准确性。加入光电隔离和电源隔离提高系统的抗干扰能力。通过采用铁电存储器避免了传统非易失性存储器有限次擦写、低速写入的缺陷。采用中断嵌套的方法开启暂存区与铁电存储单元间的数据转存,并使用状态机的思想完成转存操作。(3)完成了系统硬件电路的设计,主要包括：最小系统、供电单元、信号调理单元、铁电存储器单元、外部扩展SRAM单元、RS-485通信单元和编程下载接口单元,并使用Altium Designer 8.0完成了PCB LAYOUT、(4)在AVR Studio+WinAVR集成开发环境中完成了系统程序的编写,主要包括：外部中断触发截取数据函数、自启动数据处理功能函数、基于状态机思想的数据转存函数、铁电存储单元操作函数、RS-485通信指令系统、纠错机制功能函数和定时“喂狗”功能函数。(5)搭建了系统实验平台,通过一系列的预设通信指令,完成了对系统的验证,并给出了实验数据和对比分析。研究结果表明,本文设计的基于铁电存储器的POS机数据采集系统,可准确采集POS机的打印数据,对零售行业的监控就有较强的现实意义。
[Abstract]:As an electronic device widely used in retail industry, POS machine plays an important role in daily consumption life. It brings convenience to people at the same time. Ferroelectric memory is widely used in various fields because of its characteristics of high speed writing, higher durability of reading and writing and lower power consumption. And can be used to replace EEPROM and SRAM.Synthetical the above characteristics, this paper designs a set of POS data acquisition system which uses ferroelectric memory as storage unit to collect bill information. The main research work is as follows: (1) the working mechanism between POS mainframe and bill printer is studied systematically, and the working time sequence of SPP EPP and ECP mode is compared and analyzed. By analyzing the characteristics of print data transmission on the parallel bus, the data is buffered and latched. To improve the accuracy of collection, to add photoelectric isolation and power isolation to improve the anti-jamming ability of the system. By using ferroelectric memory to avoid the traditional non-volatile memory limited erasing. The defect of low speed writing. The method of interrupt nesting is used to open the data transfer between the temporary memory area and the ferroelectric memory cell, and to complete the design of the hardware circuit of the system by using the idea of state machine to complete the transfer operation. It mainly includes: minimum system, power supply unit, signal conditioning unit, ferroelectric memory unit, external extended SRAM unit RS-485 communication unit and program download interface unit. PCB LAYOUT is completed with Altium Designer 8.0. 4) the system program is written in the AVR Studio WinAVR integrated development environment, which mainly includes: external interrupt triggering intercepting data function and self-starting data processing function. The data transfer function based on state machine, the operation function of ferroelectric memory unit and RS-485 communication instruction system. Error correction mechanism function function and timing "feed dog" function function. 5) built the system experimental platform, through a series of preset communication instructions, completed the verification of the system. The experimental data and comparative analysis are given. The results show that the data acquisition system of POS machine based on ferroelectric memory can accurately collect the print data of POS machine. The monitoring of the retail industry has a strong practical significance.
【学位授予单位】：广西大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP274.2;TP333
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本文编号：1455714