| 摘要 |
PURPOSE:To enable the evaluation test for the characteristics of a function circuit by using a pin for signal input and a pin for initial reset provided in a general IC as test without using any pin exclusive for the test. CONSTITUTION:When a signal ''1'' is applied to a pin T1R in synchronism with the energization of a power source, a latch circuit 15 is reset, a decoder 16 selects a normal mode, its output is supplied through a gate 17 to a function circuit 18, which thus originally operates. On the other hand, a timer 11 inputs pulses to a pin I during counting, a binary counter 14 counts the pulses, the counted output is stored in a latch circuit 15 together with the output of an FF12, is decoded by a decoder 16, a signal is delivered from a testing circuit 19, and the function circuit 18 performs the evaluation test for the characteristics of a function block. When a rest signal is applied to the pin T1R at the time of completing the test, the function circuit 18 will return to a normal mode. With this configuration, the pins I and I1R are commonly used for the test, and the evaluation of the characteristics of the function circuit can also be performed. |
