800 MB/s DDR NAND Flash Memory Multi-Chip Package With Source-Synchronous Interface for Point-to-Point Ring Topology

Abstract

A 256 Gb NAND flash memory multi-chip package (MCP) includes eight stacked 32 Gb 2 bit/cell multi-level cell (MLC) die and an 11.6 mm2 HyperLink NAND bridge chip providing four internal NAND channels for concurrent memory operations. The bridge chip provides an external 1.2 V unidirectional byte-wide point-to-point source-synchronous double data-rate (DDR) interface for low power 800 MB/s operation in a ring topology. Interface power is reduced by shutting down the phase-locked loop in every second MCP and alternating between edge aligned DDR clock and center aligned DDR clock for source-synchronous data transfer from MCP to MCP.

Keywords

• Disk drives
• high speed integrated circuits
• nonvolatile memory