DIGITAL INPUT CIRCUIT AND ELECTRONIC EQUIPMENT

摘要

PROBLEM TO BE SOLVED: To provide a digital input circuit and an electronic equipment in which useless current consumption is reduced when an input line is pulled up or pulled down. SOLUTION: This electronic device is constituted of a three-state buffer 14, a switch S connected between an input line 14a and a ground line, a resistor 16 to pull up or pull down the input line 14a, a buffer 15 applying a high or low level voltage to the resistor 16, an address decoder 17 outputting a high or low level selection signal SEL based on a command from a CPU 11, and the like. When the selection signal SEL becomes a high level, the output of the buffer 15 becomes a high level and a resistor 16 acts like a pull-up resistor. When the selection signal SEL becomes a low level, the output of the buffer 15 becomes a low level and the resistor 16 acts like a pull-down resistor.