The HB52R1289E22 belongs to 8-byte DIMM (Dual In-line Memory Module) family, and has been developed as an optimized main memory solution for 8-byte processor applications. The HB52R1289E22 is a 64M x 72 x 2-bank Synchronous Dynamic RAM Module, mounted 36 pieces of 256-Mbit SDRAM (HM5225405BTB) sealed in TCP package, 1 piece of PLL clock driver, 3 pieces register driver and 1 piece of serial EEPROM (2-kbit) for Presence Detect (PD). An outline of the HB52R1289E22 is 168-pin socket type package (dual lead out). Therefore, the HB52R1289E22 makes high density mounting possible without surface mount technology. The HB52R1289E22 provides common data inputs and outputs. Decoupling capacitors are mounted beside TCP on the module board. Note: Do not push the cover or drop the modules in order to protect from mechanical defects, which would be electrical defects.