Integrated circuit memory with back end mode disable

摘要

A memory circuit is described which can operate in one of a number of operating modes. The operating mode of the memory circuit can be changed in a non-volatile manner after the memory circuit is packaged to reduce production scrap or meet market demands. Disable circuitry is described which includes an anti-fuse that can be externally selectively blown to disable an operating mode. Control circuitry included in the memory circuit enables a new operating mode after the first operating mode is disable. A method of selectively disabling an operating mode is described. A hierarchical scheme is also described for enabling a new operating mode from a group of operating modes, for example page-mode, extended data output (EDO), or burst EDO.