Serial flash memory using the Serial Peripheral Interface (SPI) utilizes a 24-bit addressing scheme that limits the maximum density to 128Mbits. However, in order to add new features, more and more applications are requiring densities greater than 128Mb. For serial flash applications requiring more than 128Mb of storage, many systems engineers have been forced to search for alternative memory solutions. While other non-volatile memory solutions will work, they do not offer the well known advantages of serial flash—such as lower pin-count, smaller footprint, simplified board layout and design, reduced system noise/EMI, and reduced system cost. Hence, the ideal solution would be a serial flash device capable of breaking the 128Mb density barrier. As a leading manufacturer and supplier of serial flash memory, Macronix has solved this problem by providing an innovative and simple operation mode that extends the addressable range from 24 bits to 32 bits. The increased address range will accommodate future serial flash memories starting with 256Mb to densities as large as 32Gb. Macronix is currently offering serial flash densities up to 256Mb, but with 32-bit addressing, there is plenty of room for future density increases.