说明：  一个电子日历时钟的汇编程序，硬件采用at89c51,ds12c887等，有三个按键用于调整日历、时钟，掉电时钟内部照常运行。有ds12c887的完整读写模块。
(An electronic calendar clock assembler, hardware used at89c51, ds12c887 and so on, there are three buttons used to adjust the calendar, clock, power-down the internal clock is running as usual. Ds12c887 have full read-write module.)