5.1 Interfacing the AT25010B/AT25020B/AT25040B on the SPI Bus

Communication to and from the AT25010B/AT25020B/AT25040B must be initiated by the SPI host device, such as a microcontroller. The SPI host device must generate the serial clock for the AT25010B/AT25020B/AT25040B on the Serial Data Clock (SCK) pin. The AT25010B/AT25020B/AT25040B always operates as a client because SCK is always an input.