AT34C02D 2 I C-Compatible Serial Presence Detect (SPD) EEPROM with Permanent and Reversible Software Write Protection 2-Kbit (256 x 8) DATASHEET Features Single 1.7V to 5.5V V Supply Voltage CC JEDEC EE1002 and EE1002A Serial Presence Detect (SPD) Compliant EEPROM Specification for use in DDR, DDR2, and DDR3 DIMM Modules 2 I C-compatible (2-wire) Serial Interface 400kHz (1.7V, 2.5V) and 1MHz (5.0V) Compatibility Multiple EEPROM Data Protection Schemes Permanent and Reversible Software Write Protection for the Lower 128 bytes Hardware Write Protection for the Entire Array Schmitt Trigger Filtered Inputs for Noise Suppression 16-byte Page Write Modes Partial Page Writes are Allowed Self-timed Write Cycle (5ms maximum) High-reliability Endurance: 1,000,000 Write Cycles Data Retention: 100 Years 8-pad 2x3mm UDFN, 8-lead TSSOP, 8-lead JEDEC SOIC, and 8-ball VFBGA Packages Die Sales: Wafer Form, Tape and Reel, and Bumped Wafers are Available Description The Atmel AT34C02D is designed to support the JEDEC EE1002 and EE1002A Serial Presence Detect (SPD) function used in DDR, DDR2, and DDR3 Dual Inline Memory Modules (DIMM). The AT34C02D provides 2,048 bits of Serial Electrically-Erasable and Programmable Read Only Memory (EEPROM) organized as 256 words of 8 bits each. The device also incorporates a permanent and reversible software write protection feature for the lower 128 bytes of the EEPROM. Once the permanent software write protection is enabled, it cannot be reversed. However, the reversible software write protection can be enabled or disabled by sending a specific command and protocol sequence. A hardware write protection function is also available and is controlled by the WP pin state. It can be used to protect the entire EEPROM contents regardless of whether or not the software write protection has been enabled. The software and hardware write protection features allow the user the flexibility to protect none, lower-half, or the entire memory array depending on the specific needs of the application. The device is optimized for use in many industrial and commercial applications where low-power and low-voltage operations are essential. The AT34C02D is available in space saving 8-pad 2x3mm UDFN, 8-lead TSSOP, 8-lead JEDEC SOIC, and 8-ball VFBGA packages and is 2 accessed via an I C-compatible 2-wire serial interface. The AT34C02D operates over a wide V range, from 1.7V to 5.5V. CC Atmel-8781D-SEEPROM-AT34C02D-Datasheet 0120151. Pin Configurations and Pinouts Figure 1-1. Pin Configurations 8-lead TSSOP 8-pad UDFN Pin Function A V A V 0 1 8 CC 0 1 8 CC A 2 7 WP A WP 1 1 2 7 A 3 6 SCL A A Address Inputs A SCL 2 2 3 6 0 2 4 5 GND SDA GND SDA 4 5 GND Ground Top View Top View SDA Serial Data SCL Serial Clock Input 8-lead SOIC 8-ball VFBGA WP Write Protect V Power Supply CC A 1 8 V A 1 8 V 0 CC 0 CC A 2 7 WP A 2 7 WP 1 1 3 6 A SCL 3 6 2 A SCL 2 4 5 GND SDA 4 5 GND SDA Top View Top View Note: Drawings are not to scale. 2 AT34C02D DATASHEET Atmel-8781D-SEEPROM-AT34C02D-Datasheet 012015