A 0.5-1 V MTCMOS/SIMOX ROM macro with low-V/sub th/ memory cells

In applying the SRAM technology to a ROM, it is necessary to use low-V/sub th/ memory cells while suppressing a leakage current. Conventional multi-threshold ROM. which consists of a high-V/sub th/ memory cell and suppresses the leakage current. operates at the supply voltage of 1 V, but there have been no memories that operate at a supply voltage down to 0.5 V. In this paper, we describe a MTCMOS/SIMOX ROM scheme with low-V/sub th/ memory cells, and a boosted word driver that makes possible high-speed operation at ultralow supply voltage of 0.5 V.