PSRAM
Psuedostatic DRAM (PSRAM), otherwise known as CellularRAM, is low-power family of memory devices intended for mobile phones. PSRAM provides both SRAM and FLASH interfaces. In the pre-smartphone era of the early-to-mid 2000s, PSRAM was intended to replace SRAM by providing a cheaper cost-per-bit cache and buffered memory solution. PSRAM parts range in capacity from several megabits (Mb) to several hundred Mb. The top speed for PSRAM in synchronous interface mode is 133MHz. Essentially, PSRAM wraps DRAM cells in an SRAM or Flash interface. Because DRAM cells are physically smaller than SRAM cells, they can be cheaper to produce. However, DRAM cells do require overhead to ensure proper data retention and that is hidden from the user and managed by the PSRAM itself. The PSRAM can operate in simple asynchronous SRAM interface mode. It can also be configured to support the NOR Flash burst interface. PSRAM is even built to be ball-out compatible with SRAM devices The initiative to create PSRAM was led by such companies as Cypress Semiconductor Corporation, Micron Technology, Qimonda, Renesas Technology Corporation, Etron Technologies, and Hynix Semiconductor. The working group has been largely inactive since 2009. Read more Read less