本文關(guān)鍵詞： POS機(jī) 數(shù)據(jù)采集器 ATmega128A FRAM　出處：《廣西大學(xué)》2014年碩士論文　論文類型：學(xué)位論文

【摘要】：作為廣泛應(yīng)用于零售業(yè)的電子設(shè)備,POS機(jī)在日常消費(fèi)生活中起著重要的作用。它給人們帶來便利的同時,也使得相關(guān)部門對零售行業(yè)的監(jiān)管變得更加困難。鐵電存儲器以其高速度寫入、更高的讀寫耐久性和更低的功耗的特點(diǎn),被廣泛應(yīng)用于各領(lǐng)域,并可以用來替換EEPROM和SRAM。綜合以上特點(diǎn),本文設(shè)計(jì)了一套以鐵電存儲器為存儲單元,用于采集票據(jù)信息的POS機(jī)數(shù)據(jù)采集系統(tǒng),主要研究工作如下：(1)系統(tǒng)研究了POS主機(jī)與票據(jù)打印機(jī)間的工作機(jī)理,通過比較分析SPP、EPP和ECP模式的工作時序,選取通用性較強(qiáng)的應(yīng)答信號/ACK作為觸發(fā)信號。(2)通過分析打印數(shù)據(jù)在并行總線上的傳輸特點(diǎn),對數(shù)據(jù)進(jìn)行緩沖和鎖存處理,提高采集的準(zhǔn)確性。加入光電隔離和電源隔離提高系統(tǒng)的抗干擾能力。通過采用鐵電存儲器避免了傳統(tǒng)非易失性存儲器有限次擦寫、低速寫入的缺陷。采用中斷嵌套的方法開啟暫存區(qū)與鐵電存儲單元間的數(shù)據(jù)轉(zhuǎn)存,并使用狀態(tài)機(jī)的思想完成轉(zhuǎn)存操作。(3)完成了系統(tǒng)硬件電路的設(shè)計(jì),主要包括：最小系統(tǒng)、供電單元、信號調(diào)理單元、鐵電存儲器單元、外部擴(kuò)展SRAM單元、RS-485通信單元和編程下載接口單元,并使用Altium Designer 8.0完成了PCB LAYOUT、(4)在AVR Studio+WinAVR集成開發(fā)環(huán)境中完成了系統(tǒng)程序的編寫,主要包括：外部中斷觸發(fā)截取數(shù)據(jù)函數(shù)、自啟動數(shù)據(jù)處理功能函數(shù)、基于狀態(tài)機(jī)思想的數(shù)據(jù)轉(zhuǎn)存函數(shù)、鐵電存儲單元操作函數(shù)、RS-485通信指令系統(tǒng)、糾錯機(jī)制功能函數(shù)和定時“喂狗”功能函數(shù)。(5)搭建了系統(tǒng)實(shí)驗(yàn)平臺,通過一系列的預(yù)設(shè)通信指令,完成了對系統(tǒng)的驗(yàn)證,并給出了實(shí)驗(yàn)數(shù)據(jù)和對比分析。研究結(jié)果表明,本文設(shè)計(jì)的基于鐵電存儲器的POS機(jī)數(shù)據(jù)采集系統(tǒng),可準(zhǔn)確采集POS機(jī)的打印數(shù)據(jù),對零售行業(yè)的監(jiān)控就有較強(qiáng)的現(xiàn)實(shí)意義。
[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.
【學(xué)位授予單位】：廣西大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2014
【分類號】：TP274.2;TP333
，

本文編號：1455714