High voltage drift drain mosfets ( dddmos ) are nowadays widely applied in circuits of power management , i / o interface , lcd drivers and etc . however , up to now a lack of a standard and accurate dddmos current model still brings much trouble in the circuit design 近年来,高压双扩散漏器件dddmos ( driftdrainmosfet )以其优良的性能被广泛地应用于电源管理、输入输出接口、 lcd驱动等电路中。然而,目前在业界缺少标准和准确的dddmos电流模型,给电路设计者带来困难。
Its hardware design was analyzed from the master module , imported equipment modules , exporting equipment modules , data storage module , other components and the problem of the printer ’ s continuous printing from interrupted position was fixed in this course ; followed by , the software design including the operating system and the application software was discussed . the kernel of linux system was transferred to the motherboard of the novel fiscal cash register as its own operating system , in which the compilation of lcd driver and the printer driver was mainly focused on , and the application software was divided into the controlled tax software , the commercial software and power - fail protected disposal software for further discussion ; finally , the systemic reliability , security and electromagnetic compatibility were evaluated 首先硬件部分主要由主控模块、输入设备模块、输出设备模块、数据存储模块等部分组成,在硬件设计中解决了发票打印机掉电续打的难题;接着对税控收款机的软件设计主要从操作系统和应用软件两个方面讨论:操作系统采用的是linux操作系统,先将linux内核移植到税控收款机主板上,着重介绍了lcd 、打印机驱动程序编写;应用软件分为税控软件、商业软件和掉电处理程序来讨论;最后,对本文设计的税控收款机系统的可靠性、安全性和电磁兼容性等方面进行分析和研究。
A typical calculator chip from rcl semiconductor inc , c9821 , is referenced and developed . the chip of the calculator consists of several function units such as rc oscillator , power management module , microprogrammed control unit ( mcu ) , register group , lcd driver and keyboard interface 在硬件方面,在完成计算器的功能模块划分的基础上,对包括rc振荡器、电源模块、 lcd显示驱动模块、键盘接口、寄存器组、微程序控制器在内的各个功能模块的系统结构和电路原理进行了分析,掌握了它们的设计方法。