The Atmel high speed, 4 Kbit SPI bus serial EEPROMs support SPI modes 0 and 3 operation. The EEPROM is organized as 512 words x 8 bits and optimized for industrial and commercial applications where low-power and low-voltage operations are essential.The EEPROM is available in a variety of space-saving packaging options at 1.8 (VCC = 1.8V to 5.5V). The three-wire serial interface consists of a data input, output, and a shift clock. All programming cycles are completely self-timed, and no separate erase cycle is required before write. Block write protection is program enabled and separate program enable and disable instructions are provided for additional data protection. Hardware data protection provided to protect against inadvertent write attempts to the status register. Any serial communication suspension can be accomplished without resetting the serial sequence.