Description
The microcontrollers in the STM32G0 Series, STM32G4 Series, STM32L4 Series, STM32L4+ Series, STM32L5 Series, STM32U5 Series, STM32WB Series, and STM32WL Series feature an internal low-power Flash memory that is able to store code and data. The applications in the X-CUBE-EEPROM Expansion Package demonstrate how to emulate an EEPROM using the internal Flash memory, thus saving the cost of external components. For the host board in P-NUCLEO-WB55, a specific example maintaining a Bluetooth® Low Energy connection and communication while processing EEPROM operations is provided. For this example, a mechanism to share efficiently the Flash memory between the two STM32WB microcontroller cores is implemented. For more details, refer to the EEPROM emulation techniques and software for STM32 microcontrollers application note (AN4894), available on www.st.com. Product status link X-CUBE-EEPROM EEPROM emulation software expansion for STM32Cube X-CUBE-EEPROM Data brief DB3326 - Rev 4 - December 2021 For further information contact your local STMicroelectronics sales office.

Features
■ Lightweight implementation and reduced footprint
■ Simple API that consists of a few functions to format, initialize, read and write data, and clean up Flash memory pages – User-configured EEPROM size – Supports 8-bit, 16-bit and 32-bit variables; supports 96-bit variables for the STM32U5 Series – Clean-up simplified for the user (background page erase) – Interrupt servicing is possible during program and erase operations
■ At least two Flash memory pages to be used for internal data management
■ Wear leveling algorithm to increase emulated EEPROM cycling capability
■ Increased EEPROM memory endurance versus Flash memory endurance
■ Robust against asynchronous resets and power failures
■ Optional protection for Flash memory sharing between the two cores of the STM32WB Series microcontrollers
■ Maintenance of cache coherency