DATA SELECTING CIRCUIT

PURPOSE:To automatically select and output a status signal side, when a status signal is varied, in a state that a pulse signal side is selected and outputted by a variation of a pulse signal. CONSTITUTION:In a state that a first and a second flip-flops 3, 4 are set, a data selector 2 selects and outputs status signals S1-S3 by an output of an AND gate 9 and when pulse signals P1-P3 are varied in such a state, its varied pulse signals are latched by a latch circuit 1 by an output of an OR gate 5, and also, a second flip-flop 4 is reset, and the data selector 2 selects and outputs latch data of the latch circuit 1. Also, when a variation is generated in the status signals S1-S3 in such a state, pulse converting circuits 10-12 detect its variation, a second flip-flop 4 becomes a set state again by an output of an OR gate 8 passing through an AND gate 7 and an OR gate 6, and the data selector 2 selects and outputs the status signals S1-S3.