The Atmel 4-Kbit SPI Serial EEPROM, organized as 512 words x 8 bits, is accessed via a 3-wire serial bus supporting SPI Mode 0 and 3 operation. It is optimized for automotive applications where low-power and low-voltage operations are essential. The EEPROM is available in two 8-lead, space-saving packaging options and operates at 2.5V (VCC = 2.5V to 5.5V). The 3-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 is provided to protect against inadvertent write attempts to the status register. Any serial communication suspension can be accomplished without resetting the serial sequence.