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一位微处理机是由美国莫托罗拉(MOTOROLA)公司于1977年推出的一种工业控制领域的可编程控制装置。系统在工作时是顺序按位执行的,EPROM地址码的选通是从低到高依次进行的。但在实际生产中,既有顺序执行的工艺流程,也有跳动执行的工序,遇到跳动执行的工序时,就得重新编程,改变内存中程序排列的秩序,这是比较麻烦的。在通常的一位机系统中,PC用八位二进制计数器串接,只可寻址256个单元,仅占EPROM内存(2k)的1/8。作者对EPROM剩余的7/8单元分别存贮不同顺序的监控程序(即不同的工艺流程所对应的程序),用手动进行外界控制。在一位机系统中,输入、输出的点数一般使用多级芯片的串接来扩展。但一位机的特点是每次只处理一位二进制数,每一时刻只有一片锁存器被选中,共余均处于禁止状态。因此,只有一块芯片作输出锁存,利用一点多枝的办法同样能起到扩展点数的作用。另外,系统的数据输入,在生产过程中有时并不需要随时对外界进行采样,而是采用一些优化数据,为此,采用一片EPROMⅡ来单独存放这些优化数据,运行的将此数据和指令同时取出来送到控制系统进行处理。同时对存贮数据的EPROMⅡ的功能端进行手动控制,以实现自动/采样输入的功能。
A microprocessor is a kind of programmable control device in the field of industrial control introduced by MOTOROLA Company in 1977. System in the work is the order of the implementation of the bit, EPROM address code strobe is from low to high in turn. However, in actual production, both the sequential execution of the process, but also beating the implementation of the process, beating the implementation of the process, you have to reprogram, change the order in the memory of the program, which is more troublesome. In a typical one-bit system, the PC is connected in octal binary counters and can address only 256 cells, making up only 1/8 of the EPROM memory (2k). The author of the remaining 7/8 EPROM units were stored in different sequences of monitoring procedures (ie, different processes corresponding to the program), with manual external control. In a computer system, the input and output points generally use multi-level chip series to expand. However, the characteristic of a machine is that it only processes one binary number at a time, and only one latch is selected at a time, and the rest are disabled. Therefore, only a chip for output latch, the use of a little more branches can also play the role of expanding the number of points. In addition, the system of data input, sometimes do not need to sample the outside world at any time in the production process, but the use of some optimized data, for this purpose, the use of a piece of EPROM Ⅱ to store these optimized data separately, running the data and instructions simultaneously Out to the control system for processing. At the same time the function of EPROM Ⅱ storage data manual control, in order to achieve automatic / sampling input function.