Difference and performance comparison between HAL and LL library of STM32

Introduction to LL and HAL libraries

LL: Low-Layer, low-level library
HAL: Hardware Abstraction Layer, hardware abstraction layer library

Compared with the hal library, the LL library is very streamlined, which is actually a streamlined library.

The configuration options for the LL library are as follows:

In STM32CUBEMX, click "Project Manager" -> "Advanced Settings" in the menu, select "Advanced Settings" in the following interface, and then select the library used after each module

Summary:

1. If the MCU used is of small capacity, then STM32Cube LL will be the best choice;

2. If you combine portability and optimization, use the STM32Cube HAL and replace some calls with specific optimized implementations to maintain maximum portability.In addition, HAL and LL can be used partially concurrently (HAL and LL cannot run concurrently for the same peripheral), or a mixed HAL and LL implementation can be used to obtain the same advantages mentioned above.

STM32 performance comparison using HAL library, standard library, LL library and register operations

Introduction

When developing stm32, the development difficulty and speed of choosing different libraries may vary greatly, and accordingly, the running performance of the developed code will also vary greatly.

The following figure shows several commonly used functions officially given: GPIO flip, TIM PWM output, ADC DMA data acquisition and DMA M2M. The running results developed by using different libraries can be used for reference and comparison, so as to meet the needs of your own development.The selection required by the project.

Summary

The law that code efficiency is inversely proportional to portability is obvious.But compared with Cube HAL, the efficiency advantage of Cube LL is still obvious, almost the same as the efficiency of directly writing registers.And at present, STM32cubeMX has begun to support the direct generation of projects using Cube LL. It is highly recommended for everyone who pursues efficiency in the future.