View Full Version : Wizard install programs on Flash while it has limited cycle?
rookery
25th September 2005, 05:00 AM
I just think about it, how many time can a flash disk be read and write? is it limited say 50000 times? what will happan if the flash dead, the phone also dead !!! am I correct ?
3waygeek
25th September 2005, 12:28 PM
You're right in that flash does have a limited number of write cycles; that limit, as I understand it, is per cell, and not per chip.
There are extra cells in the flash to accommodate failures in individual cells, sort of like spare sectors on an IDE drive. Control circuitry in the flash handles the mapping between memory address and flash cells; it also has a load balancing algorithm to ensure that all cells get roughly the same wear.
When HTC (or anyone else) designs a flash-based device, they take this kind of stuff into account, and specify parts with high enough write cycle limits to last well beyond the expected useful life of the device.
rookery
25th September 2005, 02:55 PM
You're right in that flash does have a limited number of write cycles; that limit, as I understand it, is per cell, and not per chip.
There are extra cells in the flash to accommodate failures in individual cells, sort of like spare sectors on an IDE drive. Control circuitry in the flash handles the mapping between memory address and flash cells; it also has a load balancing algorithm to ensure that all cells get roughly the same wear.
When HTC (or anyone else) designs a flash-based device, they take this kind of stuff into account, and specify parts with high enough write cycle limits to last well beyond the expected useful life of the device.
Thanks,
so, we are worry free now????? the flash won't die before I buy another phone say three years later ?
but i jsut found those
http://www.opentech.at/papers/embedded/node55.html
http://www.cygnal.org/ubb/Forum1/HTML/000197.html
which is ture ?
far182
26th September 2005, 03:33 AM
They have intellegence on the flash that disributes the writing of information accross the flash evenly. This reduces the changes of there being a problem.
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