GEIC693MDL940、IC693MDL645FPGA内工作电路主流存储器从FPM和EDO到SDR和DDR，再到DDR2，这种发展带来了***的架构、更高的密度、更快的速度、更低的电源电压、更高的带宽和更低的功耗。这些显著的技术进步提升了DRAM技术—尤其是将运算市场部分提高到更高的性能水平。DRAM技术上取得的进步伴随着多内核处理器的出现、新的操作系统，以及跨多种不同运算平台和应用的越来越多的不同要求，包括服务器、工作站、海量存储系统、超级计算机、台式电脑和笔记本电脑和外设。存储器技术的每次转变，对存储器的考虑都变得越来越复杂，但是如果清楚了解了主流的存储器如何发展的，以及其中出现的一些折中，设计师就可以选择能很好地满足他们的平台、操作系统和应用的高性能存储器。速度问题在DDR技术之前是SDR技术，在SDR技术之前，有快速页/扩展数据输出(FP/EDO)存储器。FP/EDO存储器的数据传输是异步的，意味着数据/地址/命令信号没有供参考的时钟信号。SDR技术通过提供一个时钟输入改善了这个问题，这些信号可以以这个时钟信号为基准，在时钟的上升沿(从低到高的转变)发送数据。利用与系统时钟同步的DRAM时钟引脚，可以获得比异步存储器高很多的数据速率。在2000年，市场上引入了DDRSDRAM。DDR技术通过在时钟的上升沿和下降沿传送数据，使速度相对于SDR倍增。采用DDR，每个时钟周期传送两个数据位(每根数据线)，而不是SDR的一个位。为了实现这一点，在每个时钟周期内每个数据线访问存储器阵列(数据实际存储的位置)的两个数据位。这种过程称为2字或2n预取。这里的内核时钟周期是指存储器阵列的周期时间，存储器阵列的频率为I/O缓冲器的一半和1/4的数据速率。预取使速度不断提高，改善效率并增强性能。DDR2SDRAM功能非常类似于DDRSDRAM，但是它的一些新特性使得速度更快，DDR3以DDR2为起点，获得更大的技术进步。DDR具有2n预取，DDR2具有4n预取，DDR3具有8n预取。DDR3的内部数据周期时间为外部时钟速度的1/8，内部数据总线的宽度为外部数据总线宽度的8倍。DDR3在每个内核时钟周期内，每根数据线从存储器阵列移出8个数据位到I/O缓冲器中。其他增强带宽的特性包括更低的终结电阻(RTT)值以支持更高的数据率。对于DDR2，其起始值为50Ω，DDR3的起始值为20Ω。DDR2和DDR3SDRAM的差异DDR3的技术优势DDR3实现了一系列的技术改善，这些改善强调更快的速度和更高的性能。DDR3器件设计用于高速信号，改善的引脚排列提供了更多的电源和地，这样能实现更优的电源供电。改善的电源分布和地以及改善的基准信号，这些加在一起共同改善了信号质量。DDR3D/Q阵列减小了D/Q失真，使D/Q时序更紧凑，而***布局的球珊改善了机械可靠性。针对所有应用的DDR3模块1．峰值性能提高因为DDR3的性能是DDR2的两倍，DDR3在DDR2的基础上速度进一步提高。DDR3的***低速率为每秒800Mb，***大为1,600Mb。当采用64位总线带宽时，DDR3能达到每秒6,400Mb到12,800Mb。2．电源电压DDR3的电源电压降低到1.5V，与标准的1.8VDDR2相比，低20%。这对于低数据速率的应用来说特别重要，例如移动计算。在移动计算应用中节省15%到20%的功率非常重要，因为在这种应用中功率是很重要的性能指标。DDR3的低功耗特性同样对于笔记本应用来说具有重要的优势。3．融合的驱动器与DDR2的18Ω驱动器相比，DDR3的34Ω驱动器特别针对每个通道两个模块以及点对点的系统进行了优化。DDR3SDRAM驱动器还通过降低电容、动态片上终结(ODT)以及新的校准方案改善了性能。为降低输出驱动器/终结驱动器组合的输入电容，DDR3实现了一种融合的驱动器。这种驱动器可以支持多种终结值，使用了相同的上拉和下拉驱动器结构的组合。事实上，融合驱动器的***重要优势是它能通过重复使用这些结构来减少电容—这一点是与DDR2SDRAM的一个关键的区别，后者针对输出驱动器和终结驱动器电阻分别使用了不同的结构。3HAA1001-1233HAA1001-1243HAA1001-1253HAA1001-1263HAA1001-1273HAA1001-1293HAA1001-133HAA1001-1303HAA1001-1313HAA1001-1323HAA1001-1343HAA1001-1353HAA1001-1363HAA1001-1423HAA1001-1433HAA1001-1443HAA1001-1463HAA1001-1543HAA1001-163HAA1001-1613HAA1001-1623HAA1001-1643HAA1001-1663HAA1001-1683HAA1001-173HAA1001-1723HAA1001-1733HAA1001-1743HAA1001-1763HAA1001-1813HAA1001-1863HAA1001-1893HAA1001-1963HAA1001-1993HAA1001-2003HAA1001-2013HAA1001-2023HAA1001-2073HAA1001-213HAA1001-2183HAA1001-2303HAA1001-243HAA1001-2433HAA1001-2443HAA1001-2623HAA1001-2673HAA1001-2823HAA1001-2973HAA1001-3023HAA1001-3053HAA1001-3163HAA1001-3173HAA1001-333HAA1001-3343HAA1001-3423HAA1001-3433HAA1001-3443HAA1001-3463HAA1001-3473HAA1001-393HAA1001-5003HAA1001-5013HAA1001-5133HAA1001-5193HAA1001-5223HAA1001-5253HAA1001-5263HAA1001-5313HAA1001-5783HAA1001-6033HAA1001-6043HAA1001-6053HAA1001-6063HAA1001-6073HAA1001-6083HAA1001-6123HAA1001-6133HAA1001-6143HAA1001-6163HAA1001-6223HAA1001-6283HAA1001-6303HAA1001-6323HAA1001-6363HAA1001-6583HAA1001-6683HAA1001-6703HAA1001-6723HAA1001-6913HAA1001-6953HAA1001-7003HAA1001-7013HAA1001-713HAA1001-7163HAA1001-7183HAA1001-7193HAA1001-7213HAA1001-7273HAA1001-733HAA1001-743HAA1001-753HAA1001-763HAA1001-773HAA1001-783HAA1001-793HAA1001-813HAA1001-823HAA1001-833HAA1001-863HAA1001-883HAA1001-893HAA1001-903HAA1001-973HAA1001-983HAA2010-13HAA2021-13HAA2039-1Sleeve3HAA2043-1Nut3HAA2049-13HAA2058-133HAA2092-113HAA2092-123HAA2095-123HAA2095-133HAA2099-123HAA2103-113HAA2103-133HAA2103-143HAA2103-153HAA2103-163HAA2103-183HAA2103-273HAA2104-113HAA2107-113HAA2111-13HAA2121-33HAA2126-13HAA2128-13HAA2130-13HAA2165-203HAA2166-113HAA2166-123HAA2166-133HAA2166-163HAA2166-173HAA2166-183HAA2166-193HAA2166-203HAA2166-213HAA2166-223HAA2166-233HAA2166-243HAA2166-273HAA2166-283HAA2167-113HAA2167-123HAA2167-133HAA2167-153HAA2167-163HAA2167-173HAA2167-183HAA2167-193HAA2167-213HAA2212-13HAA2218-13HAA2242-13HAA2246-13HAA2247-13HAA2280-13HAA2281-13HAA2286-43HAA2324-13HAA2325-123HAA2325-133HAA2333-13HAA2341-13HAA2355-113HAA2356-113HAA2356-123HAA2356-143HAA2367-13HAA2388-113HAA2393-13HAA2477-13HAA2484-113HAA2495-13HAA2500-13HAA2503-13HAA2504-13HAA2589-13HAA2599-13HAA2599-23HAA2599-33HAA2600-23HAA2600-33HAA2601-13HAA2601-23HAA2601-33HAA2602-13HAA2602-23HAA2602-33HAA2613-23HAA2613-33HAA2614-23HAA2614-33HAA2659-23HAA3001-133HAA3001-143HAA3001-153HAA3001-163HAA3001-183HAA3001-193HAA3001-203HAA3001-213HAA3001-223HAA3001-493HAA3001-503HAA3001-513HAA3001-523HAA3001-533HAA3001-63HAA3001-653HAA3001-73HAA3001-983HAA3001-993HAA3003-213HAA3003-263HAA3003-283HAA3003-333HAA3003-353HAA3003-503HAA3003-523HAA3003-573HAA3003-583HAA3003-593HAA3014-13HAA3014-23HAA3015-13HAA3016-13HAA3017-83HAA3018-163HAA3101-AD3HAA3101-AE3HAA3101-CC3HAA3101-CH3HAA3201-CE3HAA3201-CG3HAA3201-CH3HAA3201-EE3HAA3560-GSA3HAA3560-HSA3HAA3560-HVA3HAA3560-HWA3HAA3560-KVA3HAA3560-LHA3HAA3560-LTA3HAA3560-LUA3HAA3560-LXA3HAA3560-MEA3HAA3560-NJA3HAA3560-NKA3HAA3560-NLA3HAA3560-NMA3HAA3560-NNA3HAA3560-NPA3HAA3560-NRA3HAA3560-NSA3HAA3560-NVA3HAA3560-PDA3HAA3563-AGA3HAA3563-ARA3HAA3563-AUA3HAA3567-AA3HAA3567-AB3HAA3567-BA3HAA3567-BB3HAA3567-FB3HAA3567-GB3HAA3567-NB3HAA3573-ABA3HAA3573-ACA3HAA3573-AJA3HAA3573-AKA3HAA3909-1013HAA3909-1033HAA3909-1043HAA3911-1023HAA7601-13HAA7601-383HAA7601-433HAA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