SanDisk announced that it will begin mass-production of the first high performance 4-bits-per-cell (X4) flash memory. Using 43nm process technology, this breakthrough enables 64-gigabit (Gb) memory in a single die – the highest capacity in the industry and suitable for the most demanding storage applications.

SanDisk has also produced an advanced X4 controller, which is necessary to manage the complexities and performance requirements of X4 memory. The X4 memory chip combines with the X4 controller chip in a multi-chip package (MCP) to provide a complete, integrated and low-cost storage solution.

The company co-developed the 64Gb X4 flash memory chip on 43nm technology with Toshiba, which cooperates with SanDisk in the development and manufacturing of advanced flash memory. The new 43nm 64Gb X4 chip is the highest capacity and highest density flash memory die in the world to enter production this year, boasting a 7.8MB/sec memory write performance that is comparable with current multi-level cell technologies. SanDisk’s patented All-Bit-Line (ABL) architecture as well as the newly introduced three-step programming (TSP) and sequential sense concept (SSC) serve as key enablers to X4’s impressive performance.

SanDisk developed a number of solutions for advanced system management that address the difficulties posed by this complex 4-bits-per-cell technology. The X4 controller, developed and owned by SanDisk, utilizes a first-of-its-kind error correcting code (ECC) scheme specifically developed for use in storage systems, and tailored to support the 16 levels of distribution needed for 4-bits-per-cell.

At the 2009 International Solid State Circuits Conference (ISSCC), SanDisk and Toshiba presented a technical paper describing the key technology advancements that led to the development of 64Gb 4-bits-per-cell NAND flash memory on 43nm technology node. This announcement comes one year after SanDisk unveiled its X3 (3-bits-per-cell NAND) technology at the 2008 ISSCC and was subsequently honored with the ISSCC 2009 Lewis Winner Outstanding Paper Award.