本文提出了MCS-51系列单片机外部大容量RAM的扩展方法,使MCS-51系列单片机在一些特殊场合下得到广泛的应用。理论上系统外部扩展RAM的可行方法很多,如以P1口的某几位作为最高位地址输出、外加锁存器锁存高位地址等。本系统采用后者,以保留P1口,况且外设空间充裕。 This text has proposed the MCS-51 series one-chip computer external large-capacity RAM expansion method, make MCS-51 series one-chip computer obtain the extensive application in some special occasions. In theory, there are many feasible ways to expand RAM outside the system. For example, a few bits of port 1 are output as the highest address, plus the latch high address. The system uses the latter, in order to retain P1 port, Moreover, sufficient peripheral space.