| 摘要 |
<p>PURPOSE:To expand the application range of a ROM by a method wherein an input circuit which performs latching operation and an input circuit which performs non-latching operation are provided and one of the two input circuits is selected when mask writing is carried out. CONSTITUTION:If switches S1-S4 are connected to terminals 1A-4A when mask writing is carried out, the input of a control signal generator 3 is fixed and an input circuit 6 is connected between an input terminal 4 and internal address. In this case, as the input circuit 6 performs non-latching operation, the whole input circuit is constituted as an input circuit with non-latching operation. To the contrary, if the switches S1-S4 are connected to terminals 1B-4B when mask writing is carried out, the control signal generator 3 are connected to a control signal input circuit 2 and at the same time an input circuit 5 is connected between the input terminal 4 and the internal address. Therefore, the whole circuit is constituted as a circuit with latching operation.</p> |
