dram的刷新详解艾薇儿婚礼歌曲
stationery是什么意思In typical modern DRAM systems, thememory controller periodically issues an auto-refresh (auto-refreshis sometimes called CAS-before-RAS refresh)command to the DRAM.The DRAM chip thenchoos which rows to refresh using an internal counter, and refreshes a numberof rows bad on the device capacity. During normal temperature operation (below 85’C), the average time between auto-refresh commands(called tREFI ) is 7.8us . In the extended temperature range (between 85 _C and 95 _C), the temperature range in whichden rver environments operate [10] and 3D-stacked DRAMs are expected tooperate [1], the time between
auto-refresh commands is halved to 3.9 us [15]. An auto-refresh operation occupies all banks on the ranksimultaneously (preventing the rank from rvicing any requests) for a lengthof time tRFC, where tRFC depends on the number of rows beingrefreshed .
对外汉语专业介绍Some devices support per-bank refreshcommands, which refresh veral rows at a single bank [16], allowing forbank-level parallelism at a rank during refreshes. However, this feature is notavailable in most DRAM devices.
exos
在典型的现代dram系统中,MC周期性的向dram发送 auto-refresh (有时候这这种刷新⽅式称为CAS-bef栖息的意思>外文文献翻译
ore-RAS刷新)命令。Dram芯⽚使⽤⼀个内部计数器,来选择需要刷新哪些⾏,每⼀次刷新的⾏数和Dram的容量有关。在正常温度下(低于85‘C),auto-refresh命令的时间间隔(称为 tREFI )为7.8us,在⾼温下(介于85’C和95‘C,通常密集的服务器环境和3D dram处于这种温度下),时间间隔为3.9us.⼀个auto-refresh操作同时占有⼀个rank的所有的bank(使rank不能相应任何内存请求)的时间为 tRFC (注意:tRFC为刷新所占⽤的时间,⽽tREFI为两次刷新的时间间隔),⽽tRFC取决于刷新的⾏数。(注:这种⽅式最为常见)
剑桥商务英语培训>kiddie
新概念英语课文下载以前的Dram也允许MC通过⼀⾏⼀⾏的打开每⼀⾏的⽅式执⾏刷新操作(称为RAS-only刷新),但是由于需要额外的功耗来向总线传送⾏地址,所以这种⽅式被废弃了。
有的Dram也⽀持每个bank刷新的命令,每次同时刷新⼀个bank的多个⾏,在⼀个rank刷新的时候允许bank-level 并⾏(注:这指的是刷新rank中的⼀个bank的时候,可以访问这个rank的另外⼀个bank)
参考资料:RAIDR: Retention-Aware Intelligent DRAM Refresh,Jamie Liu Ben Jaiyen Richard Veras Onur Mutluarrived
Carnegie Mellon University
{jamiel,bjaiyen,rveras,onur}@cmu.edu