失效存储器

The controller uses the data write buffer to reduce the data access waiting time, and employs the two ways of duo channels instruction pre-fetch buffer to decrease the fetching instruction waiting time and increase the instruction pre-fetch buffer hit rate. Meanwhile, to reduce the waiting time aroused by page miss of SDRAM, a four ways of on chip stack memory is introduced. Compared with traditional controller through experiments the novel SDRAM controller gets a high reduction up to 63% in access waiting time and 64% in page miss.

该控制器采用数据写缓存方式降低了数据在存取内存时的等待时间；并引入了两组双通道预取指令缓冲器，每组双通道都用以减少取指令时的等待时间，采用两组的结构是为了增加指令预取的命中率；同时还使用了四路组关联的片上堆栈存储器来降低SDRAM的页失效频率，从而降低了因页失效而需要等待的时钟周期。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。