User Manual

MKW2xDxxxV Product Electrical Specification, Rev. 0.1
Freescale Semiconductor 43
The bytes not assigned to data flash via the FlexNVM partition code are used by the flash memory module
to obtain an effective endurance increase for the EEPROM data. The built-in EEPROM record
management system raises the number of program/erase cycles that can be attained prior to device
wear-out by cycling the EEPROM data through a larger EEPROM NVM storage space.
While different partitions of the FlexNVM are available, the intention is that a single choice for the
FlexNVM partition code and EEPROM data set size is used throughout the entire lifetime of a given
application. The EEPROM endurance equation and graph shown below assume that only one
configuration is ever used.
where
• Writes_subsystem — minimum number of writes to each FlexRAM location for subsystem (each
subsystem can have different endurance)
• EEPROM — allocated FlexNVM for each EEPROM subsystem based on DEPART; entered with
the Program Partition command
• EEESPLIT — FlexRAM split factor for subsystem; entered with the Program Partition command
• EEESIZE — allocated FlexRAM based on DEPART; entered with the Program Partition command
• Write_efficiency
— 0.25 for 8-bit writes to FlexRAM
— 0.50 for 16-bit or 32-bit writes to FlexRAM
•nn
vmcycd
— data flash cycling endurance (the following graph assumes 10,000 cycles)
Writes_subsystem =
EEPROM . 2 Å~ EEESPLIT Å~ EEESIZE
EEESPLIT Å~ EEESIZE
x Write_efficiency x n
nvmcycd