The LC374500ST is a 524288-word x 8-bit (4M) mask programmable ROM that is pin compatible with flash memory. Since this product supports the wide operating voltage range of 2.6 to 5.5 V and achieves access times of 100 ns (tCA) when VCC is between 4.5 and 5.5 V and 200 ns when VCC is between 2.6 and 5.5 V, it can be used both in high-speed 5-V systems and battery-operated 3-V systems. Since this product is pin compatible with flash memory it can replace flash memory used during prototyping and production.