How to save flash disk from corruption?

[Guest]

Hi,

Our product needs to run on the site where there is a frequent power
failure. We want the system should work like as an appliance (for ex washing
machine, electric oven, etc..) ie the user should simply power off & on and
there should not be any shutting down procedures. The OS should not get
corrupted due to frequent switching off / power failure. Our configuration
x86, flash disk with xpe.

So i am trying to wirte protect my os, sw as well as hardware. I can use EWF
in the xpe to enable the software write protect and i need to physically
write protect the flash medium (which i feel necessary to prortect file
corruption due to power failure). But in most of the flash disks like
M-systems disk-on-chip there is no wite protect switch to physically write
protect the disk.

How to save my Flash disk from failure?.

How flash disks are proteceted from physical failure?. How to make our
product as a rugged device.

Can any one tell me how peoples are protecting their device from above such
failures??.

Thanks
Saravanan

 

[Slobodan Brcin \(eMVP\)]

Saravanan,

M-Systems USB DiskOnChip actually have write protect switches.
They do not have physical switch, but trough proprietary commands you can place uDOC in WP mode. Since WP is implemented in firmware
then you can consider this as very close to pure hardware protection where you would disconnect write signal from flash chip.

Regards,
Slobodan

 

[Guest]

Thank you Slobodan. I found M-systems had different versions like
iDisk-on-chip with IDE interface, FFD IDE Plus, etc... I am totally confused
on which one to use. Can you please tell me what is the difference between
those device. Basically we are looking for cheaper version of flash with IDE
interface. Also i am worried about the write cycles Write/Erase cycles.

--
Thanks
Saravanan

Saravanan,

M-Systems USB DiskOnChip actually have write protect switches.
They do not have physical switch, but trough proprietary commands you can place uDOC in WP mode. Since WP is implemented in firmware
then you can consider this as very close to pure hardware protection where you would disconnect write signal from flash chip.

Regards,
Slobodan

 

[Slobodan Brcin \(eMVP\)]

Saravanan,

To my knowledge all DiskOnChip series use wear-leveling internally so write-cycles count should not be a problem.

Read about wearleveling and bad-block management algorithms:
http://www.m-systems.com/content/Corporate/Technology/TrueFFS.asp

I can't tell you about IDE DOC devices since I have never seen or used them. You can search for more info of M-Systems site.
What I know for certain is that uDOC devices are supported by M-Sys for usage with XPe and that they are really fast.

Regards,
Slobodan

Thank you Slobodan. I found M-systems had different versions like
iDisk-on-chip with IDE interface, FFD IDE Plus, etc... I am totally confused
on which one to use. Can you please tell me what is the difference between
those device. Basically we are looking for cheaper version of flash with IDE
interface. Also i am worried about the write cycles Write/Erase cycles.