W958D6DB

W958D6DB 256Mb Async./Burst/Sync./A/D MUX 1. GENERAL DESCRIPTION Winbond x16 ADMUX products are high-speed, CMOS pseudo-static random access memory developed for lowpower, portable applications. The device has a DRAM core organized. These devices are a variation of the industrystandard Flash control interface, with a multiplexed address/data bus. The multiplexed address and data functionality dramatically reduce the required signal count, and increase READ/WRITE bandwidth. For seamless operation on a burst Flash bus, Winbond x16 ADMUX 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 Winbond x16 ADMUX 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. Winbond x16 ADMUX products include two mechanisms to minimize standby current. Partial-array refresh (PAR) enables the system to limit refresh to only that part of the DRAM array ...