DDR I/II总线的失效分析方法探索

【关键字】DDR，时序，建立时间，保持时间，眼图，逻辑分析仪，示波器
【摘要】 DDR全名为Double Data Rate SDRAM ，简称为DDR。现在市场上的DDR已经发展到了DDR II，速度可以支持到667MT/s。FBD（Fully Buffered DIMM）也即将在市场上推出，速度更快。DDR总线走线数量多，速度快，操作复杂，容易出现问题，给测试和分析带来了很高的挑战。本文对DDR总线的失效情况进行了分析，总结一些实践经验，给出了测试分析的一些思路和方法。
【Key Words】 DDR, Timing, Setup Time, Hold Time, Eye Diagram, Logic Analyzer, Oscilloscope
【Abstract】SDRAM (Synchronous Dynamic Random Access Memory) is a critical component of computers and other electrical equipments. About several years ago, a new type of SDRAM,called DDR(Double Data Rate) was introduced,which memory clocks is on both edges. DDR II is the second generation of memory technologies,and it has four different form factors for more mainstream produces such as DIMM, SO-DIMM, Mini DIMM, Micro DIMM,and the speed is up 667MT/s.There are more 100 traces in DDR bus,and it is difficult to debug them.This article classifies the error types and provides some debugging method combining some experience.
DDR总线概览
DDR全名为Double Data Rate SDRAM ，简称为DDR。现在市场上的DDR已经发展到了DDR II，速度可以支持到667MT/s。FBD（Fully Buffered DIMM）也即将在市场上推出，速度更快。DDR I和DDR II对比参考表1。