单片机密码保存器

1 摘要

在现代社会中数字化方向的发展在给我们的生活来巨大便利的同时，也带给我们一些小小的麻烦，我们需要记忆的密码越来越多，住宅与办公室的安全防范、单位的文件档案、财务报表以及一些个人资料 的保存等多以加锁的办法来解决。若使用机械式钥匙开锁人们常需携带多把钥匙,使用极不方便,且钥匙 丢失后安全性即大打折扣。银行卡，信用卡，EMAIL,甚至家中的门锁。由于这些密码的重要性，即使把它们存储在电脑的某个角落之中，我们仍然担心由于种种原因而造成的密码泄露或遗失。

Atmega8单片机用来存储密码是非常合适的。首先相对于家用PC，它是工业级的产品，更有效地保证存储的密码不会因为外部的温温度等环境条件的变化而被破坏。其次，ATMega8不需要操作系统，直接运行用户自行编写的程序，具有很好的个体性。再次，其内部可加密的EEPROM存储器相对于外部EEPROM存储器增加了通过非法手段直接读取EEPROM中内容的难度，从而提高了安全性。

本设计的内容包括AVR单片机M8主控芯片。在相同的系统时钟下AVR运行速度快。芯片内部的FLAHH/EEPROM/SRAM容量较大。多种型号的FLASH/EEPROM都可以反复烧写全部支持在线编程烧写。多种频率的内部RC振荡器、上电自动复位。零外围电路也可以工作。每个IO口都可以推换驱动的方式输出高电平，驱动能力强。显示为一片LCD1602液晶，支持串行输入，节省端口，绿色节电。PS2键盘输入。

此外本设计还具有打字练习功能，可由此系统来练习打字，加快电脑打字录入速度。

关键词：Atmega8嵌入式单片机；LCD1602液晶；PS2键盘输入；ISP在线下载 2 Abstract

In modern society the development of digital direction to our lives to the

great convenience at the same time,also brought us some little trouble. We need

to remember the password more and more , residential and office security, units

of the document files, financial statements as well as some personal information

such as the preservation of a solution to the locking. The use of mechanical keys

to unlock many people often need to carry keys, the use of a very inconvenient,

and the key is lost or greatly reduced after the security. Bank cards, credit cards,

EMAIL, and even door locks home, because of the importance of these

passwords, even if they are stored in a corner of the computer, we remain

concerned about a variety of reasons caused by leakage or loss of password.

Atmega8 as an embedded microcontroller, used to store the password is

very appropriate. First of all, as opposed to home PC, it is industrial-grade

products, more effectively to ensure that the password will not be stored in

external temperature and temperature changes in environmental conditions were

broken. Secondly, ATMega8 do not need the operating system directly to the

preparation of the user running the program, with very good individual. Once

again, its internal EEPROM memory can be encrypted as opposed to an external

EEPROM memory through illegal means to increase the direct reading of the

difficulty of the contents of EEPROM, resulting in improved security.

The design includes single-chip AVR chip M8 master. In the same system

clock to run faster under the AVR. Chip internal FLAHH / EEPROM / SRAM

larger capacity. Several models of FLASH / EEPROM programmer can be

repeated all the support programmer online programming. Multi-frequency 3 internal RC oscillator, power-on reset automatically. Zero can also be the work

of the external circuit. Each IO port can drive up the way for high output,

driving ability. LCD1602 LCD display for one to support the serial input port

savings, green power. PS2 keyboard input.

In addition this design also has the function of typing practice, this system

can be to practice typing, typing speed up the entry speed of the computer.

Key words: Atmega8 embedded single-chip； LCD1602 LCD； PS2

keyboard； ISP online download

4 目录

摘要 .................................................................................................... 1

Abstract ............................................................................................. 2

1绪论 ................................................................................................. 6

1.1密码的起源与发展 ................................................................................. 6

1.2 密码的组成 ............................................................................................ 7

1.3 本文的研究内容、目的与意义 ............................................................ 8

第2章 密码保存器的硬件设计 .................................................... 9

2.1 单片机 .................................................................................................... 9

2.1.1单片机的历史及发展 .................................................................. 9

2.1.2单片机介绍 ................................................................................ 11

2.1.3单片机的应用领域 .................................................................. 13

2.1.4单片机的选型 ........................................................................... 15

2.2 液晶显示部分 ................................................................................. 17

2.2.1 液晶显示屏的分类 ................................................................. 18

2.2.2 液晶显示的特性 ........................................................................ 19

2.2.3 1602液晶显示屏的管脚功能 .................................................... 20

2.2.4 1602液晶显示屏的字符集和指令集 ................................... 21

2.3 ISP下载 ................................................................................................ 22