View tc74hc138p datasheet:

TC74HC138P IL00 C-MOS 3-TO-8 LINE DECODER/DEMULTIPLEXER —TOP VIEW— 1 15 A Y0 IN A 1 VDD 16 2 14 B Y1 3 13 C Y2 IN B 2 15 OUT Y0 12 Y3 11 Y4 4 IN C 3 14 OUT Y1 EN1 10 Y5 5 9 EN2 EN Y6 IN 4 13 EN1 OUT Y2 7 6 EN3 Y7 IN 5 12 EN2 OUT Y3 INPUTS OUTPUTS IN EN3 6 11 OUT EN C B A Y7 Y6 Y5 Y4 Y3 Y2 Y1 Y0 Y4 0 x x x 1 1 1 1 1 1 1 1 OUT 7 10 Y7 OUT 1 0 0 0 1 1 1 1 1 1 1 0 Y5 1 0 0 1 1 1 1 1 1 1 0 1 8 GND 9 OUT 1 0 1 0 1 1 1 1 1 0 1 1 Y6 1 0 1 1 1 1 1 1 0 1 1 1 1 1 0 0 1 1 1 0 1 1 1 1 1 1 0 1 1 1 0 1 1 1 1 1 1 1 1 0 1 0 1 1 1 1 1 1 1 1 1 1 0 1 1 1 1 1 1 1 EN = • • EN3 0 : LOW LEVEL EN1 EN2 1 : HIGH LEVEL x : DON’T CARE