Description of STM32L4/L4+ HAL and low-layer drivers User manual,The HAL driver layer provides a generic multi-instance simple set of APIs (application programming
interfaces) to interact with the upper layer (application, libraries and stacks).
The HAL driver APIs are split into two categories: generic APIs which provide common and generic
functions for all the STM32 series and extension APIs which include specific and customized functions
for a given line or part number. The HAL drivers include a complete set of ready-to-use APIs which
simplify the user application implementation. As an example, the communication peripherals contain
APIs to initialize and configure the peripheral, manage data transfers in polling mode, handle interrupts
or DMA, and manage communication errors.
