US Patent 7379374 Virtual ground circuit for reducing SRAM standby power

A method of operating a memory circuit having a plurality of blocks of memory cells (400-404) is disclosed. The method includes storing data in the plurality of blocks of memory cells. A first block of memory cells (400) is selected in response to a first address signal (RAY0). A row of memory cells (430-436) in the first block of memory cells is selected in response to a second address signal (RAX0). A first voltage is applied to a first power supply terminal (412) of the first block of memory cells in response to the first address signal. A second voltage different from the first voltage is applied to a first power supply terminal (412) of another block of memory cells (402) of the plurality of blocks of memory cells. Data is retained in the other block of memory cells.