at89c51作的一个时钟程序和电路，可作为电子时钟设计的参考，用c51写的程序，protel99se画的电路图，程序均已调试通过，可作为万年历时钟！-at89c51 for the procedure and a clock circuit, as an electronic clock to the reference design, with the decoder written procedures protel99se painting circuit, debugging proc