SYSTEM OF SETTING OPERATION MODE OF SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PURPOSE:To set a specific operation mode from a plurality of operation modes by providing one shift register which has been connected from one operation- mode setting terminal. CONSTITUTION:A shift register 4 which uses a mode-setting terminal 1 of a semiconductor integrated circuit as a data input is constituted in such a way that a data is shifted by a signal, of a shift clock signal line, generated at an AND circuit 6 by individual input signals to a clock input terminal 2 and to a reset input terminal 3. An input data 1' for operation-mode setting use is input from the mode-setting terminal 1 in synchronization with the signal of the shift clock signal line 7. A shift clock 7' is generated as an output signal from the AND circuit 6 by a clock 2' and a reset signal 3' which is input from the reset terminal 3. The clock 2' is a system clock which operates a semiconductor integrated circuit and is always oscillated. A data from individual flip- flops 8 constituting the shift register 4 is output from an output terminal 5; an operation mode is judged at the inside of the semiconductor integrated circuit when a reset is released.