Green NAND device (GND) driver with DRAM data persistence for enhanced flash endurance and performance

摘要

A Green NAND Device (GND) driver application queries AC line and battery status and then stores an image of processor states and caches and a resume routine to DRAM when power failure occurs. A DRAM image is then stored to flash memory for a persistent mode when battery power is available. The image in DRAM may be a partial image that includes entries, flushed caches, processor contexts, ramdisks, write caches, and a resume context. Endurance of flash memory is increased by a Super Enhanced Endurance Device (SEED) SSD. In a power down mode, the GND driver limits DRAM use and only caches in DRAM data that can be deleted on power down. Host accesses to flash are intercepted by the GND driver and categorized by data type. Paging files and temporary files cached in DRAM are optionally written to flash.

主权项

1. A Green NAND Device (GND) driver with a persistent mode comprising:
a flash memory that retains stored data when power is lost; a persistent processor image generator that copies data from a host processor state and from a processor cache memory to a volatile memory when a persistent mode power down routine is activated to generate a host processor image; a persistent resume image stored in the volatile memory when the persistent mode power down routine is activated; a persistent image generator that copies data from a host volatile memory to the flash memory when the persistent mode power down routine is activated to generate a persistent restore image, wherein persistent mode is activated and executed when sufficient battery power is available; a restore image loader that reads the persistent restore image from the flash memory to the host volatile memory when the persistent mode routine was activated at a prior power down, and executes the persistent resume image from the volatile memory to restore the host processor image.