51系列单片机不象Z80系列有自己的配套接口电路,人们大多使用Z80系列的芯片如:8155、8255、8979……等做为其接口电路。可是在使用中常常会碰到一种故障,即在开发系统上调试完成的程序,在目标机上却无法脱机运行,有时连续开关电源或连续按动“REST”键偶而也能进入正常状态。查硬件接线也无错误,进一步深入检查,可发现这类问题大多数都是由于接口电路未能按程序要求进行初始化而造成的。形成这个故障的原因笔者认为是由于8051系列电路和Z80系列电路复位特性不一致而造成的。现以 51 series MCU unlike the Z80 series has its own matching interface circuit, most people use Z80 series chips such as: 8155,8255,8979 ...... as its interface circuit. However, in use often encounter a fault that finished in the development of debugging system, the target machine can not run offline, and sometimes a continuous power supply or continuous press “REST” key and can enter the normal state. Check the hardware wiring is also no error, further in-depth examination, we can find that most of these problems are due to the interface circuit failed to initialize the program requirements. The reason for the formation of this failure I believe that is due to 8051 series circuit and Z80 series circuit reset characteristics caused by inconsistencies. Now