A circuit and method erase at power-up all data stored in a DRAM chip for increased data security. All the DRAM memory cells are erased by turning on the transistors for the DRAM storage cells simultaneously by driving the wordlines of all the cells to an activated state. With all the devices turned on, the data stored in the memory cells is erased as the voltage of all the cells connected to a common bitline coalesce to a single value. In a preferred embodiment, the wordlines are all turned on simultaneously during a power on reset period. Preferably a power on reset signal is used to drive each logic gate of the pre-decoder portion of the address decoder in order to assert all the wordlines.