Emulating Data EEPROM for PIC18 and PIC24 Microcontrollers and dsPIC Digital Signal Controllers

Many applications store nonvolatile information in the Flash program memory using table write and read operations. Applications that need to frequently update this data may have greater endurance requirements than the specified Flash endurance for the device. The alternate solution of using an external, serial EEPROM device may not be appropriate for cost-sensitive or pin-constrained applications. This application note presents a third alternative that addresses these issues: an algorithm that features an interface similar to an internal data EEPROM, uses available program memory, and can improve endurance by a factor as high as 500.