When using multiple bit logic devices, verify that inputs do not ever float. In many cases, functions or parts of functions of digital logic devices are unused, for example, when only two inputs of a triple-input AND gate are used or only 3 of the 4 buffer gates are used. Do no leave such input terminals unconnected because the undefined voltages at the outside connections result in undefined operational states. In all circumstances, observe the rules specified below. Connect all unused inputs of digital logic devices to a high or low bias to prevent them from floating. The logic level that applies to any particular unused input depends on the function of the device. Generally the logic level is tied to the Gnd or Vcc, whichever is the better choice.