The OKI MSM531655E is a 524,288-double words x 32-bit or 1,048,576-words x 16-bit CMOS Mask ROM with an asynchronous page read mode. Each page is organized 8 double words x 32-bit or 16 words x 16-bit. It operates on a single 5.0V power supply and is TTL compatible. The chip's asynchronous I/O requires no external clock assuring easy operation. A power-down mode provides low power dissipation when the chip is not selected. The CE and OE pins are provided as control signals that permit three-stated output allowing easy memory expansion on a system bus.The MSM531655E is suited for use as large capacity fixed memory for microcomputers and data terminals.