| 摘要 |
PURPOSE:To quickly carry out tests for the abnormal working of a program and an address bus by setting an address where all address buses are set at '1' as well as a 0 address to an address bus and securing an exclusive OR between a signal line led from an input/output controller and said address bus. CONSTITUTION:A 0 address is set to an address bus line 12 and the comparison data is set at '0'. Then an exclusive OR is secured by an exclusive OR circuit 4 and therefore a stack '1' of the line 12 is known. Then an address FFFF is set to the line 12, the comparison data set at '1' respectively and an exclusive OR is secured by the circuit 4. Thus a stack '0' of the line 12 is obtained. In other words, if a signal adverse to an input signal is supplied to a part of the line 12, the exclusive logic element of that area has discordance of input. Then '1' is outputted from the logic element and an NOK signal is outputted to an output line 28. |
