摘要：【中文】本发明公开了51单片机18位扩展成128位接口的电路，使用简单并行接口扩展方式，将8组相同的电路分别与51单片机相连，每组电路包括74LS273芯片、74LS244芯片和两个74LS32芯片，74LS273芯片的清零端MR接电源，时钟端CLK接一个74LS32芯片的输出端，该74LS32芯片的输入端1个引脚接单片机WR引脚P3.6，D0～D7引脚与51单片机的P0.1～P0.7引脚相连；74LS244芯片的两个选通端OE引脚接另一个74LS32芯片的输出端，该74LS32芯片的输入端1个引脚接单片机RD引脚P3.7，Y端8个引脚依次与51单片机P0.1～P0.7相连，将51单片机的18个引脚扩展，得到64路输入引脚和64路输出引脚，共128个引脚。将51单片机本身的32个输入输出引脚扩展成64个输入引脚，64个输出引脚和14个输入输出引脚，共142个引脚，克服了51单片机引脚较少的缺点。 【EN】The invention discloses a circuit for expanding 18 bits of a 51 single chip microcomputer into a 128-bit interface, wherein 8 groups of same circuits are respectively connected with the 51 single chip microcomputer by using a simple parallel interface expansion mode, each group of circuits comprises a 74LS273 chip, a 74LS244 chip and two 74LS32 chips, a zero clearing end MR of the 74LS273 chip is connected with a power supply, a clock end CLK is connected with an output end of a 74LS32 chip, 1 pin at the input end of the 74LS32 chip is connected with a WR pin P3.6 of the single chip microcomputer, and pins D0-D7 are connected with pins P0.1-P0.7 of the 51 single chip microcomputer; two gating end OE pins of a 74LS244 chip are connected with an output end of another 74LS32 chip, 1 pin of an input end of the 74LS32 chip is connected with a pin P3.7 of a single chip microcomputer RD, 8 pins of a Y end of the 74LS32 chip are sequentially connected with 51 single chip microcomputers P0.1-P0.7, 18 pins of the 51 single chip microcomputers are expanded, 64 input pins and 64 output pins are obtained, and 128 pins are total. 32 input and output pins of the 51 single chip microcomputer are expanded into 64 input pins, 64 output pins and 14 input and output pins, and 142 pins are used, so that the defect that the 51 single chip microcomputer has fewer pins is overcome.