| 摘要 |
PURPOSE:To make a test by generating logic level [1] or [0] in a needed state and at a needed point in time from a buffer circuit driving an external connection circuit connected to LSI according to a control signal obtained by a control circuit. CONSTITUTION:When testing clocks are inputted to controller 11, output circuits A and B generate logic [0] or [1]. When logic [0] or [1] is transferred to output circuit B, control signal D transferred from logic circuit 10 can control tri-state 14 to high impedance or low impedance. When logic [0] or [1] is transferred to output circuit A, information signal C transferred from logic circuit 1 makes it possible to obtain logic [0] or [1] from exclusive-OR circuit 12-1 corresponding to the input. |
