| 摘要 |
PURPOSE:To eliminate a change in electric power supply at testing time, and perform accurate measurement by forming a test circuit of testing means of respectively independently operable plural systems. CONSTITUTION:A register clock Rck from a test signal output part 23 is inputted to a register clock input of a dummy testing circuit 12 of a gate array 26 with built-in RAM. According to this, a test clock Tck from the output part 23 and test output data DOUT are respectively held by a dummy register and a data output register. A dummy output signal DTCK and data DOUT fed back from the array 26 are inputted to a data control device 25 through a test signal input part 24. The device 25 measures apparent RAM macro access time containing delay time according to the data Door. Next, dummy information such as delay time intervened in the apparent access time is obtained according to the signal DTCK fed back from the circuit 12, and RAM macro access time is found from these. In this way, a test can be performed by driving only a necessary circuit. |
