SPD EEPROM Supports JEDEC DDR2 Standard

The M34E02 is an application specific EEPROM that fulfills the Serial Presence Detect (SPD) function used in the new generation of higher speed memory modules conforming to the JEDEC DDR2 specification. The SPD is used on the latest versions of the DIMMs that provide most of the system memory in desktop PCs, printers and set-top boxes. A set of parameters defined by the DDR2 standard is stored and locked in the lowest 128 bytes of the device. These record information such as the module?s access speed, memory size, configuration and manufacturer. Access to this data by the CPU is via an I2C serial interface. The device has 256 Kb (256 bytes) of total memory. The upper half of the memory remains free for scratchpad use. The device is fabricated in CMOS and operates over a supply voltage range of 1.7V to 3.6V. It allows random and sequential read modes and Byte Write and Page Write (up to 16 bytes) operations. Data retention is rated for 40 years and memory can be read/written to beyond 1 million times. STMICROELECTRONICS INC., Lexington, MA. (781) 402-8592.