Serial Quad I/O (SQI) Flash Memory The Serial Quad I/O™ (SQI™) family of 4-bit, multiplexed I/O, serial-interface, flash-memory devices features a sixwire, 4-bit I/O interface that allows for low-power, high-performance operation in a low pin-count package, occupying less board space and ultimately lowering total system costs. All members of the 26 Series, SQI family are manufactured with SST propri... More about this product.