| 摘要 |
PURPOSE:To obtain an interface circuit for level conversion capable of performing the voltage level conversion of an output signal fitting in a voltage at a target board side operated by a 3V system power source at an in-circuit emulator side operated by a 5V system power source. CONSTITUTION:An interface circuit 11 which transmits an input/out-put signal between an in-circuit emulator side circuit 12 and a target board 13 is equipped with a first level conversion circuit 14 which converts a 5V system signal level to a 3V system signal level, a second level conversion circuit 15 which converts the 3V system signal level to the 5V system signal level, a level clamping circuit 16 which clamps the input side of the first level conversion circuit 14 to the source voltage of the 3V system, and a gate circuit 17 which performs the directional control of the first level conversion circuit 14 and the second level conversion circuit 15 based on a control signal supplied on an in-circuit emulator side. |
