| 摘要 |
<p>PURPOSE:To avoid such a case where the clock switching action is not secured owing to a transient phenomenon produced in a clock switching mode, by providing a means to monitor the working state of the system, a means to suppress the system working, a means to give a switching instruction to a clock supply source for switching clock cycles and a means to release said suppression mode. CONSTITUTION:The working of a processor 2 is suppressed despite a request given for transfer of data with an information processing unit 5 if a communica tion display flag 41 is read out and at the same time logic '1' is set to a com munication suppression flag 12. It is checked whether data are transferred or not with an information processing unit 6 within a program to be executed by the processor 2 after logic '0' is set if the flag 41 is kept at logic '1' in an under-processing state or immediately the flag 41 is kept at logic '0' respec tively. Then the transfer of data is suppressed with the unit 6 in the same way. In such a way, the processor 2 gives an instruction to a clock supply unit 3 to change the cycle of a clock 34 after suppressing the transfer of data.</p> |
