Lockout circuit and method for preventing metastability during the termination of a refresh mode
US5400289A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 15, 1994 |
| Grant date | Mar 21, 1995 |
| Priority date | — |
| Expiry date | Jul 15, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C11/4076
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A circuit and method for preventing glitches from occurring during a termination of a self-refresh mode when a race condition exits between an external row address strobe signal* (RAS*) transitioning to an inactive state and an internally generated self-refresh timing signal transitioning to an inactive state. The circuit of the invention includes a pulse circuit for generating an active self-refresh cycle pulse and a lock out circuit. The lock out circuit is responsive to the external RAS* signal and the active self-refresh cycle pulse. The lock out circuit locks out the effect of the active self-refresh cycle pulse when an external RAS* signal transitions to an inactive state prior to the generation of the active self-refresh cycle pulse and locks out an effect of a transition of the external RAS* signal to an inactive state when the active self-refresh cycle pulse is present.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.