Copyright © 2021 STMicroelectronics
The STM32Cube HAL and LL, an STM32 abstraction layer embedded software, ensure maximized portability across STM32 portfolio.
The portable APIs layer provides a generic, multi instanced and simple set of APIs to interact with the upper layer (application, libraries and stacks). It is composed of native and extended APIs set. It is directly built around a generic architecture and allows the build-upon layers, like the middleware layer, to implement its functions without knowing in-depth the used STM32 device. This improves the library code reusability and guarantees an easy portability on other devices and STM32 families.
The Low Layer (LL) drivers are part of the STM32Cube firmware HAL that provides a basic set of optimized and one-shot services. The Low layer drivers, contrary to the HAL ones are not fully portable across the STM32 families; the availability of some functions depends on the physical availability of the relative features on the product. The Low Layer (LL) drivers are designed to offer the following features:
Backward compatibility ensured by legacy defines