| 摘要 |
PURPOSE:To detect an input of lower priority at a simple circuit constitution easily, by obtaining an output detecting the reception of the low priority, in a system handling binary information for an electronic computer or the like. CONSTITUTION:When an input data (al) goes to ''1'', an output of output terminals B1, B0 of a priority encoder circuit 1 is unchanged to remain as ''1,1'', an output of the output terminals B1, B0 of a priority encoder circuit 2 is ''1,0'', then an output of an OR circuit 7 goes to ''1'', and the change in the input state is detected surely. That is, since the priority encoder circuits 1, 2 are connected with opposite priority, the encoded output is symmetrical only for a single input data without fail, and the symmetry is lost for plural input data, then the change in the input state is detected by comparing the outputs of the circuits 1 and 2. |
