CONTROL CIRCUIT FOR ACTION MODE OF SEMICONDUCTOR INTEGRATED CIRCUIT

摘要

PURPOSE:To designate plural action modes without increasing the number of elements by decoding the outputs of (n) pieces of flip-flops which latch the signal levels during an active period of a system clock of the K-th phase and producing an action mode setting signal. CONSTITUTION:The system clocks CP0-CP3 of 4 phases having phase shifts so that the active periods of high levels are never overlap with each other are applied to the clock terminals of flip-flops 5-8. Then these flip-flops latch the signal levels of a control input terminal 4 during the active periods of system clocks. A decoder 3 decodes the outputs of flip-flops 5-8 and produces signals needed for each action mode. Thus 2<4> ways of combination are secured for input signals to be applied to the decoder 3 by supplying the signals synchronizing with system clocks through the terminal 4. As a result, the total number of settable action modes can be increased without increasing the number of exclusive terminals.