| 摘要 |
PURPOSE:To miniaturize a circuit element by reducing the number of external terminals necessary for testing an internal circuit in a test circuit. CONSTITUTION:A test circuit 6 outputting a test start signal and a test completion signal on the basis of the test signal 11 applied to a single external terminal 1 is equipped with a reversal signal forming part 2 inputting the test signal and alternately reversing an output signal 12 corresponding to the level change of the signal 11 and an inverter 3 to which the output signal of the inverted signal generating part is applied as input. Further, the test circuit 6 is equipped with a first gate 4 to which the output signal 12 of the inverted signal forming part 2 and the test signal 11 are applied as inputs and a second gate 5 to which the output signal 13 of the inverter 3 and the test signal 11 are applied as inputs. The output signal of either of the first and second gates 4, 5 is used as a test start signal and the output signal of the other one of them is used as a test completion signal. |
