Semiconductor integrated circuit device
US4879681A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 5, 1989 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Jan 5, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C8/06
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A semiconductor memory device includes an input circuit and an output circuit. To prevent the erroneous operation of the input circuit by the noise which develops at the time of the change of the output signal of the output circuit, the threshold voltage of the input circuit is changed, or an internal signal generated by the internal circuit is fixed to a predetermined level. In an output circuit having a tri-state output function, the threshold voltage of the input circuit is changed when the output is brought into the high impedance state, or the internal signal generated by the input circuit is fixed to a predetermined state. Using these arrangements it is possible to prevent the erroneous operation of the input circuit by the noise occurring when the output is brought into the high impedance state. Furthermore, in an output circuit having a tri-state output function, the threshold voltage of the input circuit is changed when the output signal of the output circuit is brought into the high impedance state, too, when the output signal changes. This makes it possible to prevent an erroneous detection of the level of the input signal which might otherwise be caused by the noise.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.