| 摘要 |
PURPOSE:To reduce the required number of man-four by obtaining a frame clock signal of a clock distribution circuit, the phase relation and period of the clock signal automatically at a fixed accuracy. CONSTITUTION:A reference composite signal (a) of a reference clock signal and a synchronizing reference frame clock signal is formed and supplied to the clock distribution circuit 1 to be tested. A frame clock signal (b) to be tested and a clock signal (c) to be tested are formed on the basis of the composite signal (a) and returned to a testing device 2. A calculating circuit 6 is counted up by the signal (c) and an initializing signal (d) and a inverted clock signal (e) are formed by the signal (b) and inputted to the counting circuit 6. When the counting circuit 6 is counted up under the state that the signal (d) is inputted, an initial value is set up and coincidence between the signal (b) and a carry signal (g) is detected on the basis of a reference frame clock signal (i) and a reference clock signal (j).
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