24C04 512x8(4k) Serial CMOS EEPROM.

Features:

• Low Voltage and Standard-Voltage Operation
• 2-wire Serial Interface
• Schmitt Trigger, Filtered Inputs for Noise Suppression
• Bi-directional Data Transfer Protocol
• 100kHz and 400kHz Compatibility
• Write Protect Pin for Hardware Data Protection
• 8-byte Page (1K, 2K), 16-byte Page (4K, 8K, 16K) Write Modes
• Partial Page Writes are Allowed
• Self-timed Write Cycle (10mS max)
• High-Reliability, 1 Million Write Cycles, 100 Year Data Retention