Adesto Technologies' AT25DFxxx block erase serial Flash family features variable-sized page programming. Any number of bytes, from a full page down to a single byte, can be programmed in one operation. Densities currently range from 512 Kbits to 64 Mbits. To increase system performance while minimizing system pin count, AT25DFxxx serial Flash devices feature clock speeds up to 100 MHz and support SPI, dual-I/O, and quad-I/O interfaces. The individual sector protection and sector lock-down schemes of the AT25DFxxx devices allow flexibility in protecting vital code and/or data including critical boot routines, whether located in the top, bottom, or any part of the array. Voltage options include 1.65 V, 2.3 V, and 2.7 V minimum devices to help improve battery life, minimize voltage rails, and reduce LDO and level-shifter requirements and costs.