Method of recognizing a card using a select signal during a determination mode and switching from low to high resistance after the determination

Abstract

A memory card is provided in which power consumption is reduced by the pull-up resistor of an input terminal and a misoperation induced by the pull-down resistor of a host apparatus is prevented. The memory card has a select terminal connected to the pull-up resistor. When the mode of the memory card is determined based on an input from the select terminal, a relatively low resistance value is selected for the pull-up resistor of the select terminal before a determination timing and the pull-up resistor is restored to an initial resistance value after the mode determination. A relatively high resistance value reduces a leakage current consumed by the pull-up resistor of the select terminal. When a pull-down resistor is connected to the terminal of a memory card host to which the memory card is attached, if the resistance value of the pull-up resistor is excessively high, it is influenced by the drawing in of a current by the pull-down resistor. If the resistance value of the pull-up resistor of the select terminal is lowered at the time of mode determination, an adverse effect of the lowering of a potential by the pull-down resistor can be circumvented.