| 摘要 |
PURPOSE:To remarkably decrease the EMI noise emitted from a terminal by suppressing a control signal to an external memory and variation of an output value of a bus, in the case of accessing a memory of the inside. CONSTITUTION:The microcomputer is provided with an internal storage means 11 for storing various data and programs, a bus control means 14 for executing read-out of the program and read-out and write of the data by an access to this internl storage means 11 or an external storage means, an instruction executing means 15 for executing the program read out of the internal storage means 11 or the external storage means 12 by this bus control means, and a bus 24 for inputting and outputting the address and the data, on a single semiconductor substrate. The bus control means 14 executes an access to the internal storage means 11 and the external storage means 12, and in the case the bus control means 14 executes an access to the internal storage means 11 a signal state variation of a control signal which is outputted to the outside from a semiconductor substrate and executes an access to the external storage means 12 and bus 24 is suppressed. |
