Microcomputer providing output clock signal - has selection control circuit for setting output of multiplexer to supply clock signal to circuit external to microcomputer, and to e.g. time circuit, A=D converter and serial input=output circuit within microcomputer

摘要

The microcomputer has a central processing unit (2) and a number of peripheral circuits (5a..5k) supplied with respective input clock signals ( phi a.. phi k). One of these clock signals is selected via a clock selection circuit (7), for supply to an external circuit outside the microcomputer, in response to a clock selection control signal (10) from a clock selection control circuit (9). Pref. the clock signal selection circuit includes a multiplexer, the clock selection control circuit having a register in which the required clock signal is logged, e.g. as corresponding bit data information. ADVANTAGE - Allows provision of different clock outputs without increased number of external terminals.