摘要 |
A high endurance, short retention NAND memory is used as a read cache for a memory of a higher level of non-volatility, such as standard NAND flash memory or a hard drive. The combined memory system identifies frequently read logical addresses of the main non-volatile memory or specific read sequences and stores the corresponding data in cache NAND to accelerate host reads. This may also reduce host's DRAM requirements. In some arrangements, special commands or partitions can be used by operating system to identify these fast read areas. The main non-volatile memory will typically also maintain a back-up copy of data in the cache NAND. In some embodiments, the read cache can be implemented as a middle layer between the host and storage system, say as an SATA-SATA bridge dongle to boost read access for frequently read data or specific patterns, such as a boot sequence. |