Now know that there are three kinds of refresh, refresh, refresh, asynchronous refresh, question, about the refresh, refresh is to read and write first, then refresh a line of time is a cycle time or two access cycle? Then there was a dead time in the centralized refresh, refresh the three conditions when a refresh line the entire memory can not go ahead with other, speaking, reading and writing, after all to address line cable, then such as scattered refresh, for one, the cycle time to flush a fourfold increase, that the latter half of this also can't read and write for other don't also calculate the dead time? And dead time or at most 2 ms in this way, because it's in every access period refresh, refresh and asynchronous, 128 x128, for example, every 15.6 microseconds refresh memory stop to read and write in a line, so calculate down in 2 ms asynchronous refresh the whole stop to read and write with concentration is consistent, refresh only benefit is to meet emergency asynchronous refreshes the refresh time don't have to wait that long, so... Meng it all

CodePudding user response:

In general are asynchronous refresh, reading and writing hit will have to wait

CodePudding user response:

reference 1/f, fog oasis response:

is asynchronous refresh commonly, read and write hit will have to wait for

So what is the meaning of the dead time, in my understanding of the centralized and asynchronous within 2 ms dead time is consistent, just distracted the asynchronous refresh the time, as to refresh, dead time, the longest available access time the shortest, understand it right? And refresh time is an access cycle or two access cycle o , Tang Shuo fly in the fourth chapter in the book of computer constitute principle sample 4.8 refresh cycle time is twice as much access, but other areas are doubled, bosses, genuflect is begged solve

CodePudding user response:

The refresh time if the SDRAM, he is capacitance model, is the charge and discharge time, reading and writing is also a charge and discharge, it'll be easier to understand the storage period and refresh cycle