Method and apparatus for anticipatory selection of external or internal addresses in a synchronous memory device

摘要

A method and apparatus are disclosed for selecting either an external column address or an internal column address in a synchronous memory device. The external or internal address is selected by decoding command signals applied to the memory device. If the command signals correspond to a read or a write memory access, an external column address is selected. If the command signals correspond to a burst read or write memory access, an internal column address is selected. Significantly, the command signals are decoded prior to the transition of a clock signal that initiates a memory access so that a column address decoder is already connected to the proper column address source prior to the start of a memory access.