Some applications require you to store data that wont be lost if the power goes down. Usual solutions involve either using an on-chip EEPROM or external memory devices.
This app note from Microchip provides an alternative that allows you to store your data in the programming memory without having the usual low rewrite cycles associated with this approach. The algorithm described in the app note moves the stored date around the free programing memory to increase the rewrite cycle efficiency up to 500 times.
Emulated data EEPROM is an effective solution for cost-sensitive applications that require high-endurance, nonvolatile data memory. Applications suited for Microchip Technology’s cost-effective MCU and DSC devices can employ unused program memory and increase nonvolatile data endurance by a factor in excess of 500. This “effective endurance” can be customized by selecting the number of program memory pages, size of emulated data EEPROM and the erase/write limit. This flexible algorithm will enable you to add high-endurance data EEPROM to your applications.