PURPOSE: To determine the true transmission time between the terminal pins in high speed, by remarkably reducing the measuring time through determination of the time delay with a simple preprocessing, when arbitrary terminals of the circuit element such as LSI are shortened.
CONSTITUTION: At the first step, the terminal pins p1...pn are sectioned into, e.g., two groups(even and odd number groups) as shown in the circuit board 6, and the parts among the pins p(n-1), pn, are respectively shortened. By using the board 6, the connection between the driver 2 and the receiver 3 is sequentially selected to measure the transmission time(A) among p(n-1), pn. Further, in the second step, as shown in the board 7, the parts between p2, p3...pn, p1 are respectively shortened. By using the board 7, the connection between the driver 2 and the receiver 3 is selected and the transmission time(B) among p3, p2...pn, p1 is measured. Further, the delay time T2 is determined when the driver 2 is connected to arbitrary terminal pi and the receiver 3 to terminal pj. Thus, true transmission time T can be given with T1WT2, by measuring the transmission time T1 between the terminals pi and pj.
KANEKO AKIRA