W968D6DA

W968D6DA 256Mb Async./Page,Syn./Burst CellularRAM 1. GENERAL DESCRIPTION Winbond CellularRAM™ products are high-speed, CMOS pseudo-static random access memories developed for low-power, portable applications. The device has a DRAM core organized. These devices include an industrystandard burst mode Flash interface that dramatically increases read/write bandwidth compared with other lowpower SRAM or Pseudo SRAM offerings. To operate seamlessly on a burst Flash bus, CellularRAM products incorporate a transparent self refresh mechanism. The hidden refresh requires no additional support from the system memory controller and has no significant impact on device READ/WRITE performance. Two user-accessible control registers define device operation. The Bus Configuration Register (BCR) defines how the CellularRAM device interacts with the system memory bus and is nearly identical to its counterpart on burst mode Flash devices. The Refresh Configuration Register (RCR) is used to control how refresh is performed on the DRAM array. These registers are automatically loaded with default settings during power-up and can be updated anytime during normal operation. Special attention has been focused on standby current consumption during self refresh. CellularRAM products include three mechanisms to minimize standby current. Partial array refresh (PAR) enables the system to limit refresh to only that part of the DRAM array that contains essential data. Temperature compensated refresh (TCR) use...