| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a portable information terminal allowing power supply in either of two kinds of communication interfaces, and having reduced production cost by commonizing a conversion circuit of DC voltage and power supply voltage supplied through a connector in USB communication or in rewriting of a control program based on UART communication. <P>SOLUTION: This portable information terminal 1 having a UART interface and a USB interface allowing the power supply comprises: the connector 2 used for both the communication interfaces, having a power terminal common to both the communication interfaces; an interface identification part 12 identifying the communication interface in use through the connector 2; and a connector power supply circuit 3 converting the power supply voltage supplied from the connector 2 on the basis of an identification result of the communication interface, and performing the power supply. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
