Changes

Total Bytes Written TBW = [capacity * P/E cycles] / WAF

where WAF is the ''Write Amplification Factor''. WAF takes into account the '''actual''' amount of data written to the memory when performing write operations. This is due to the fact that non-volatile flash memorysmemories are organized as an array of sectors that can be individually erased or written. Often, the size of erase sectors and write sectors are different. That is why, in the case of NAND flashes for instance, they are named differently (blocks and pages, respectively). WAF varies largely depending on the workload. If it is not known for the application under discussion, it can also be measured experimentally (see the following example for more details). Once the TBW is calculated, the expected lifetime can be estimated with this equation: LT = TBW / D where D is the amount of data written in the unit of time of interests (month, year, etc.). ====Example: embedded Linux system equipped with a raw NAND flash memory and UBIFS file system====This example shows how to estimate the lifetime of a raw NAND flash memory used in an embedded Linux system making use of the UBIFS file system. Specifically the memory p/n is by TBD. This  According to the datasheet, the number of P/E cycles is . The capacity is . For the sake of simplicity, it is assumed that the file system makes use of the entire memory. Otherwise, only the capacity of the partition of interest has to be taken into account. Regarding the WAF, it is assumed it is 2. This means that for each byte written by the user-space applications and daemons, two bytes are actually saved onto the memory.  TBW = ( * ) / 2 =  Assuming that the user-space software writes TBD gigabytes every year, the expected lifetime is  LT = = years =====Experimental measurement of the '''actual''' written data=====