| 摘要 |
PROBLEM TO BE SOLVED: To surely discriminate an IC card as a start stop(SS) 5V rated card, an SS 3V rated card or a synchronizing card without installing an excess equipment. SOLUTION: An interface with an IC card ms switched to 3V and activated by using a card voltage switching means in a power supply control circuit (101), and at the time of receiving an Answer to Reset (ATR), the card is processed as a 3V rated card (103). When there is no ATR, the IC card is non- activated as a 5V rated card or a synchronizing card (104). Then the interface with the IC card is switched to 5V and activated (105), and when an ATR exists at the time (106), the card is processed as a 5V rated card (107). When there is no ATR, the card is processed as a synchronizing card (108). |
