| 摘要 |
PURPOSE:To make it possible to make unit tests after mounting by equipping an IC with a logic circuit and memory circuit which process and memorize test patterns, memory circuit stored with rigth-answer values which correspond to test, patterns and comparator circuit which compares them. CONSTITUTION:The IC is composed of control circuit 103, read-only memory circuits 104 and 106, selector circuit 105, logic circuit 107, comparator circuit 108, etc., and input terminals 101 and 102 are supplid with a test mode operation command and non-test mode operation respectively. As a result, circuit 103 commands circuit 105 to send a signal from terminal 102 to circuit 107, which sends a signal selected by circuit 105 to output terminal 110. Circuit 103, on the other hand, reads out the test pattern of a word from circuit 104 and commands circuit 105 to send a signal from circuit 104 to circuit 107. Then, a right-answer value equivalent to the pattern is read out by circuit 106 and compared by circuit 108, so that they agree, the display of a test end will be done at terminal 111. |
