一个 Quartus II 工程，芯片为EP3C55F484C8，是一个简单的保险箱密码锁。包含分频器、键盘去抖、8选1选择器、扬声器模块、动态扫描模块等多个模块。
主要功能：
1.　　保险箱上设有密码输入和钥匙锁双重保险。
2.　　当密码输入正确后，左边的指示灯亮，此时插入钥匙即可打开保险箱；当密码输入错误后，右边的指示灯亮，发出报警信号，此时需要重新输入密码。
3.　　保险箱的密码可根据需要随时更换。(A Quartus II project, the chip is EP3C55F484C8, is a simple safe lock. It includes frequency divider, keyboard shake, 8 selector 1 selector, loudspeaker module, dynamic scanning module and so on.
Main functions:
1. the safety box is provided with double insurance of password input and key lock.
2. when the password is correct, the indicator on the left is bright. At this time the key can be opened to open the safe. When the password is wrong, the indicator on the right is bright and the alarm signal is sent. The password is reentered at this time.
3. the cipher's password can be changed at any time.)