| 摘要 |
A method and circuit for processing switch closures in a passive network (100) having switches (S1 ... Sn). The passive network (100) generates an output voltage in response to a switch closure. The circuit comprises a comparison circuit (206), coupled to the passive network, for comparing the output voltage to a reference voltage. A decoder (212), coupled to the comparison circuit, decodes the switch closure if the output voltage is within a predetermined range, and does not decode said switch closure if the output voltage is not within the predetermined range. The circuit differentiates between input ranges in a passive network keypad which allows the proper processing of meaningful key presses, while ignoring inadvertent or superfluous key presses, thereby conserving power and processor time. |
