View cat25c256 datasheet:

CAT25C128/256 128K/256K-Bit SPI Serial CMOS E2PROM FEATURES 100,000 Program/Erase Cycles 5 MHz SPI Compatible 100 Year Data Retention 1.8 to 6.0 Volt Operation Self-Timed Write Cycle Hardware and Software Protection 8-Pin DIP/SOIC, 16-Pin SOIC, 14-Pin TSSOP Zero Standby Current and 20-Pin TSSOP Low Power CMOS Technology 64-Byte Page Write Buffer SPI Modes (0,0 &1,1) Block Write Protection Commercial, Industrial and Automotive – Protect 1/4, 1/2 or all of E2PROM Array Temperature Ranges DESCRIPTION out (SO) are required to access the device. The HOLD The CAT25C128/256 is a 128K/256K-Bit SPI Serial pin may be used to suspend any serial communication CMOS E2PROM internally organized as 16Kx8/32Kx8 bits. Catalyst’s advanced CMOS Technology substan- without