Bank address mapping according to a bank hold time with dynamic random access memories

摘要

A system and method for refreshing data in a dynamic random access memory ("DRAM") is provided where the system comprises a data memory comprising a plurality of memory banks, an image memory in signal communication with the data memory for translating an internal address of each of the plurality from memory banks to a corresponding external address, a mapping comparator in signal communication with the mapping memory for selectively activating a memory bank according to its external address, a refresh address generator in signal communication with the mapping comparator for selectively refreshing the activated memory bank according to its external address, and a refresh counter in signal communication with the Refresh address generator for signaling a refresh according to the maximum required refresh time of the activated memory bank; and where the corresponding method of determining the maximum required refresh period for each of the respective memory banks, prioritizing the memory banks according to their respective refresh periods, using the memory banks in the order of their respective priorities, selectively deactivating at least one of the memory banks in reverse order of their respective ones Prioritizations and the refresh of only the remaining, not deactivated memory banks.