说明：  This document provides implementation instructions for the DDR3 interface
(This document defines the DDR3 SDRAM specification, including features, functionalities, AC and DC characteristics, packages, and ball/signal assignments. The purpose of this Specification is to define the minimum set of requirements for JEDEC compliant 512 Mb through 8 Gb for x4, x8, and x16 DDR3 SDRAM devices. This specification was created based on the DDR2 specification (JESD79-2) and some aspects of the DDR specification (JESD79). Each aspect of the changes for DDR3 SDRAM operation were considered and approved by committee ballot(s). The accumulation of these ballots were then incorporated to prepare this JESD79-3 specification, replacing whole sections and incorporating the changes into Functional Description and Operation.)