| 摘要 |
PURPOSE:To make it possible to input information for measuring the characteristics of DC and AC in an integrated circuit simply, by switching buffer circuits into a cascade connection state. CONSTITUTION:When a switching signal is inputted to a switching signal input terminal 10, information in a first buffer circuit 4-0 is inputted to a second buffer circuit 4-1 by switching circuit 5-1$5-n. All the buffer circuits 4-0-4-n in a peripheral buffer part 2 are connected in cascade. The information, which is inputted to the input terminal 7-0, is circulated through the peripheral buffer part 2 in an integrated circuit 1 and outputted from an output terminal 7-n. Therefore, measurement of the characteristics of the high/low level logical amplitudes at the output terminal, which is provided in the peripheral buffer part 2, can be performed without inputting a function checking pattern in an internal logic circuit part 3. Since the information, which is inputted to the input terminal 7-0, is circulated through the peripheral buffer part 2 in the integrated circuit 1 and outputted from the output terminal 7-n, the delay time from the input terminal 7-0 to the output terminal 7-n is measured and the AC characteristics are obtained. The delay time in all the buffer circuits 4-0-4-n in the integrated circuit 1 can be measured. |
