A system and method for refreshing data in a dynamic random access memory ("DRAM")
is provided, where the system includes a data memory having a plurality of memory
banks, a map memory in signal communication with the data memory for translating
an internal address of each of the plurality of memory banks into a corresponding
external address, a map comparator in signal communication with the map memory
for selectively enabling a memory bank in accordance with its external address,
a refresh address generator in signal communication with the map comparator for
selectively refreshing the enabled memory bank in accordance with its external
address, and a refresh counter in signal communication with the refresh address
generator for signaling a refresh in accordance with the maximum required refresh
time of the enabled memory bank; and where the corresponding method includes determining
the maximum required refresh period for each of the memory banks, respectively,
prioritizing the memory banks in accordance with their respective refresh periods,
utilizing the memory banks in order of their respective prioritizations, selectively
disabling at least one of the memory banks in reverse-order of their respective
prioritizations, and refreshing only the remaining non-disabled memory banks.
