| 摘要 |
PURPOSE:To make it possible to omit manual operation by switching an external test clock by means of an automatic testing machine at the time of testing a printed circuit board. CONSTITUTION:Since the potential of a selecting terminal 4-1 is usually held at an 'H' level by a pull-up resistor R, a switch 4 is held as shown by the sold line and a clock (7MHz) oscillated from a clock oscillator 2 is supplied to an internal control circuit 5 through the switch 4. At the time of executing a test, a test rod in the automatic testing machine comes into contact with a wiring connected to the terminal 4-1 and turns the potential of the terminal 4-1 to zero, so that the switch 4 is switched as shown by the dotted line and a test clock inputted from the other test rod to a test clock input terminal 3 is supplied to the circuit 5 through the switch 4. While controlling the test clock, a test signal is extracted from the wiring on a prescribed position of the circuit 5 by the other test rod to execute the operation test of the circuit 5. |
