EEPROM serial

The Microchip AT25256B provides 262,144 bits of Serial Electrically Erasable Programmable Read-Only Memory (EEPROM) organized as 32,768 words of 8 bits each. The device is optimized for use in many industrial and commercial applications where low-power and low-voltage operation are essential. The AT25256B is available in space saving JEDEC SOIC, TSSOP, UDFN, and VFBGA packages. The AT25256B is enabled through the Chip Select pin (CS) and accessed via a 3-Wire interface consisting of Serial Data Input (SI), Serial Data Output (SO), and Serial Clock (SCK). All programming cycles are completely self-timed, and no separate erase cycle is required before write. Block Write protection is enabled by programming the status register with one of four blocks of Write Protection. Separate Program Enable and Program Disable instructions are provided for additional data protection. Hardware Data Protection is provided via the WP pin to protect against inadvertent write attempts. The HOLD pin may be used to suspend any serial communication without resetting the serial sequence.

• Serial Peripheral Interface (SPI) Compatible
• Supports SPI Modes 0 (0,0) and 3 (1,1)
  • Describes Mode 0 Operation
• Low-voltage and Standard-voltage Operation ?
  • VCC = 1.8V to 5.5V
• 20MHz Clock Rate (5V)
• 64-byte Page Mode and Byte Write Operation
• Block Write Protection ?
  • Protect 1/4, 1/2, or Entire Array
• Write Protect (WP) Pin and Write Disable Instructions for Both Hardware and
  • Software Data Protection
• Self-timed Write Cycle (5ms max)
• High Reliability ?
  • Endurance: 1,000,000 Write Cycles ?
  • Data Retention: 100 Years
• Green (Pb/Halogen-free/RoHS Compliant) Packaging Options
• Die Sales: Wafer Form, Waffle Pack, and Bumped Wafers