单片机扩展片外RAM,用到的芯片有373,62256这里包涵了测试与串口调试等程序,可以用于扩展调试与串口通讯调试等-Single-chip expansion of chip RAM, the chips used here have 373,62256 includes the testing and debugging, such as serial procedures, can be used to expand the debugging and debug serial commu