| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve safety of a card device and to reduce wasteful power consumption. <P>SOLUTION: An internal circuit of the card device is operable in one of a first operation mode (SD1) where the data is transferred to a host device by using a part (DATO) of data pins and the remaining data pins (DAT1-DAT3) are not used, a second operation mode (SPI) where the data is transferred from the card device to the host device through a part of the data pins, the remaining data pin are not used, and the data is transferred from the host device to the card device through a command pin (CMD), and a third operation mode (SD4) for transferring the data by using the data pins. A data reception control circuit sets a data receiving circuit in the reception mode when the internal circuit is in the third operation mode, and sets the data receiving circuit in a fixed mode when the internal circuit is in the first operation mode and the second operation mode. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
