Detailed Explanation of STM32 HAL Library Clock System
The STM32 HAL (Hardware Abstraction Layer) Library provides a structured way to configure and manage the clock system in STM32 microcontrollers . The clock system is crucial because it determines the speed at which the CPU, peripherals, and buses operate. This guide explains the HAL clock initialization process, clock tree, and configuration methods . 1. STM32 Clock Tree Overview The STM32 clock system is highly flexible, allowing multiple clock sources and distribution paths. The main components are: A. Clock Sources Source Description Typical Use HSI (High-Speed Internal) 8-16 MHz RC oscillator (low accuracy, no external component) Fallback clock, default at startup HSE (High-Speed External) 4-48 MHz crystal/oscillator (high accuracy) Main system clock, PLL input LSI (Low-Speed Internal) ~32 kHz RC oscillator (low power, low accuracy) RTC, watchdog timer LSE (Low-Speed External) 32.768 kHz crystal (high accuracy) RTC, ...