| 摘要 |
PURPOSE:To read variable data in a short time by providing a check circuit for a change in bit needed in terms of precision for the purpose of reading data of bit constitution varying continuously. CONSTITUTION:For example, when the output of counter COUN consists of two words of eight bits of CPU block CPUB, CPUB resets change check circuit LSBC for the lowest bit needed in terms of precision prior to the reading of the value of the counter. Then, CPUB inputs data from input port MSW for the upper digits of COUNT and input port LSW for the lower digits and stores them in CPUB before inputting data from circuit LSBC stored with that the lowest bit has changed. Judging from a single-bit signal from circuit LSBC, it is discriminated whether the value of the counter can be read or not with needed precision. Consequently, it is required to read the value of the counter only once and read time of data can greatly be shortened. |
