Main menu


Test Principle and Main Points of SSD Power - Down Protection

Strong state hard drive If you should utilize FTL to do the coherent location and the physical location between the change, if the SSD read, compose, erase and other typical work on account of irregular shut down, may cause planning table due to past the point where it is possible to refresh and lost There is a shortcoming that the SSD can not be perceived by the framework.

Simultaneously, so as to improve peruse and compose execution, generally use SDRAM to do the reserve, if the way toward perusing and recording experienced unusual force, SDRAM information might be past the point where it is possible to compose Nand Flash information misfortune, or update the planning table past the point where it is possible to compose Nand Flash The planning table is absent.

Anomalous force disappointment brought about by the wonder

SSD irregular force disappointment for the most part there are three sorts of disappointment marvel:

1, SSD can not duplicate the framework distinguishing proof, the need to revamp the planning table or by basic and rough approach to re-creation can be utilized;

2, commonly after force disappointment, SSD there are a ton of "new awful square";

The instrument behind the new terrible square is that when the SSD peruses, composes, or deletes ineffectively, it will be distinguished as an awful square. Obviously, these squares are not so much awful squares, since they are unusual Power disappointment brought about by an inappropriate judgment.

3, SDRAM information misfortune;

Basic shut down security component

Each shut down assurance component to comprehend extraordinary, distinctive for the client, the security instrument is totally unique, by and large there will be the accompanying two practices:

1, spare all the information in SDRAM

Strange shut down, SDRAM all information must be completely composed to Nand Flash, when all is said in done, SDRAM limit is set to 1000% of the measure of SSD exposed limit, for little limit SSD, SDRAM need to compose Nand Flash information Relatively little, through the super capacitor or tantalum capacitor can keep on composing information. Be that as it may, on the off chance that the SSD limit is sufficiently enormous, for instance: 8TB, at that point, SDRAM need to compose Nand Flash information will be extremely huge, if still depend on super capacitor or tantalum capacitor to do control gracefully, will definitely confront the accompanying three precarious issue:

a, the requirement for more tantalum capacitor particles to do the security, in the genuine designing practice, this is an intense test, the architects face the thickness, the standard size breaking point, PCB territory isn't sufficient to utilize;

b, regardless of whether there is sufficient capacitance to do the insurance, when the usage of the "restart", the SSD won't start appropriately, you should initially close down for quite a while before restarting, in light of the fact that: SSD need to put all the tantalum capacitor after force Identified;

c, when the utilization of a couple of years after the tantalum capacitor or super capacitor subsequent to maturing, when the tantalum capacitor power gracefully can not accomplish the underlying plan target esteem, the client despite everything has information misfortune after influence misfortune or SSD can not distinguish the expected dangers, in the event that the underlying structure That is, to do repetitive capacitors, at that point, will come back to the issue "b" passing cycle.

It is satisfying that the issues of b and c are ideal answers for take care of these prickly issues just need the specialists enough psyche and experience as it were.

2, just spare the SDRAM client information, without sparing the planning table

This will diminish the utilization of SDRAM and the utilization of tantalum capacitors, "don't spare the planning table" doesn't imply that the planning table is lost, simply don't spare the last information compose update map, when the SSD re-power, Looking for the last planning table to spare the new information kept in touch with re-assemble the planning table, the downsides of this methodology isn't sufficient instrument to set the sensible, at that point revamp the planning table will be longer, SSD sets aside some effort to ordinary access to typical

For controllers without SDRAM plan, all information is composed legitimately to Nand Flash. At the point when information is lost, the information that isn't composed to Nand Flash will be come back to the host. On the off chance that no extra information should be spared, High dependability necessities of the application, no SDRAM configuration is top dog, its delegate is a German modern brand ace, its solitary downside is that the presentation isn't sufficient, truth be told, numerous applications and the requirement for the best, and Is "sufficient" execution.

Test strategies and standards

Explicit test, SSD need as a framework plate and as a circle from the two instances of testing, so the primary circle and do from the circle test technique is the main distinction is that the principle plate need to test the PC to control off the machine, and from the circle no one but SSD can be on the force off.

an, individually, of the SSD as a clear circle, information is written in the 25% and half when composing information, the compose information for 85% and 3000, separately, the unusual shut down 100% test compose information, each down And the force on time period seconds;

The standard of composing distinctive limit information to the circle is: When the SSD compose a specific measure of information, the foundation started to trash assortment, trash assortment implies that the movement of information, information relocation implies that the planning table updates, as of now Abnormal force disappointment is typically an issue.