Datasheet

15
Software and Hardware Solutions for the 32-bit Designer
Data EEPROM Emulation for PIC18, PIC24 and
PIC32 Microcontrollers and dsPIC Digital
Signal Controllers
Ref Application Note: AN1095, Ready-to-Use Solution
Summary
Microchip has expanded its product portfolio to include a
wide variety of cost-effective PIC microcontrollers without an
internal data EEPROM. Many applications store non-volatile
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 library presents a
third alternative that addresses these issues. This algorithm
features an interface similar to an internal data EEPROM,
uses available program memory and can improve endurance
by a factor as high as 500.
Key Features
■ Easy-to-use application interface
■ Memory sizes of 0 to 255 words per block
■ Total EEPROM memory size limited only by Flash size
■ Endurance increased by a factor of up to 500
■ Endurance can be further increased by allocating
additional program memory
Applications
■ Designs require to stored user-definable parameters
■ Frequently updated calibration or adjustable parameters
■ Saving critical data due to power failure