| 摘要 |
PURPOSE:To minimize the occupancy of a terminal, also to make a malfunction due to noise difficult to occur, and to execute sufficiently a test item by forming a test signal by a clock generating circuit and plural bit counters, etc. CONSTITUTION:Both a reset input signal 1 and a test input signal 2 go to ''1'', the output of a clock generating circuit 3 goes to ''0'', the reset input terminal R of a plural bit counter 4 of 2 bit, etc. goes to ''1'', thereafter, when the signal 1 goes to ''0'' and a clock input terminal CL goes to ''1'' by an output ''1'' of the circuit 3, the counter 4 is brought to increment and the output is varied. Subsequently, three kinds of 2 bit test signals except ''00'' for showing a non-test state in a 2 bit output outputted by the counter 4 are outputted. By the constitution in which said signals 1, 2 are not treated as independent ones and also plural test input signals are not combined, the occupancy of the terminal is minimized, also the probability of generation of a malfunction caused by a fact that two input signals both go to ''1'' due to noise is made small, and also various test items can be executed sufficiently. |
