Abstract:

This video tutorial offers a detailed guide to utilizing key on-chip peripherals of the STM32G4 series microcontroller. It systematically covers the functionality and implementation of the On-Chip Loader (OCL) for initial device programming, the critical role of Watchdog Timers (WDG) for system safety with a practical code example, and an in-depth exploration of the High-Resolution Timer (HRTIM) for generating precise and complex Pulse-Width Modulation (PWM) signals. The tutorial provides C code examples using the HAL library, explains configuration steps for each peripheral, and concludes with a practical application scenario, troubleshooting tips, and key takeaways for developers working on demanding applications like motor control and digital power conversion.

A Technical Guide to STM32G4 Peripherals: OCL, WDG, and HRTIM

• 0:00:38 Introduction to Key Peripherals: The tutorial outlines the core components of the STM32G4 ecosystem for advanced applications.

  • On-Chip Loader (OCL): A built-in bootloader for initial programming of the microcontroller's flash memory.
  • Watchdog Timers (WDG): Independent safety timers (IWDG and WWDG) that reset the system to prevent crashes or deadlocks.
  • High-Resolution Timer (HRTIM): A highly specialized timer designed for precise PWM generation, featuring dead-time insertion and fault handling, crucial for power electronics and motor control.

• 0:04:11 Using the On-Chip Loader (OCL): The tutorial explains the procedure for initial device programming.

  • Process: To use the OCL, you must configure the device's boot pins, connect it to a PC via a serial interface (UART, SPI, etc.), and use software like STM32CubeProgrammer to flash the application code.

• 0:07:15 Implementing the Independent Watchdog (IWDG): A practical example demonstrates how to set up the IWDG for system safety.

  • Function: The IWDG is configured with a timeout period. The application must periodically "kick" the watchdog by calling a refresh function.
  • Demonstration: The code intentionally enters an infinite loop after 5 seconds, preventing the refresh. This causes the IWDG to time out and trigger a system reset, demonstrating its ability to recover from a software fault.

• 0:12:10 Generating PWM with the High-Resolution Timer (HRTIM): The video provides a code walkthrough for generating a precise PWM signal.

  • Configuration: The code initializes the HRTIM, setting the period (to define PWM frequency) and the compare value (to define the duty cycle).
  • Key Takeaway: The PWM duty cycle can be dynamically updated during runtime by changing the timer's compare register, allowing for real-time control.

• 0:17:18 Observing the Output: To verify the code is working, an oscilloscope or logic analyzer should be connected to the configured GPIO pin (PB6 in the example) to view the generated PWM waveform.

• 0:17:50 Exploring Advanced HRTIM Features: The HRTIM is capable of much more than basic PWM. Its advanced features include:

  • Automatic dead-time insertion to protect power converter hardware.
  • Fault inputs to rapidly shut down PWM outputs during overcurrent or other fault conditions.
  • Synchronization of multiple timers to create complex, multi-phase waveforms.
  • Burst mode operation for generating precise pulse trains.

• 0:18:50 Practical Application Scenario: The tutorial suggests how to combine these peripherals in a safety-critical motor control system.

  • The HRTIM generates the high-resolution PWM signals to drive the motor.
  • The IWDG ensures the motor control firmware never gets stuck in a dangerous state.
  • The OCL is used for initial programming, which can later be extended with a custom bootloader for firmware updates.

• 0:19:32 Troubleshooting Tips: Common sources of error include incorrect clock configurations and wrong GPIO pin settings. A debugger is an essential tool for examining peripheral registers to identify configuration mistakes.