| 摘要 |
PURPOSE:To surely prevent a test program from starting up improperly by providing a check circuit consisting of a level detector, a comparison part, and a level matrix, and inputting in series plural signals with different levels to a connection terminal. CONSTITUTION:A check circuit 22 consists of a level detector 23, a comparison part 24, and a level matrix 25, and checks whether a request for the start up of the test program in an IC card is possible or not, and a terminal Reset is connected to the detector 23. And to the terminal Reset, plural multivalue signals with different levels other than a normal reset signal are inputted in series synchronizing with a clock signal phi at a terminal CLOCK. Next, an input signal is inputted to the comparison part 24 through the level detector 23, and it is compared with the serial level information stored in advance at the level matrix 25 at the comparison part 24, and it is possible to start up the test program only when they coincide. In this way, the improper start up of the test program can be surely prevented. |
