GPIO_PORT_WDG->ODR ^= GPIO_PIN_WDG;

### STM32 GPIO Port Bit Toggling Using ODR Register For performing a bit toggle operation on an STM32 microcontroller's GPIO pin using the Output Data Register (ODR), one can directly manipulate this register to change the state of output pins. The following C function demonstrates how to implement such functionality: ```c void Toggle_GPIO_Pin(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin) { /* Check the parameters */ assert_param(IS_GPIO_ALL_PERIPH(GPIOx)); assert_param(IS_GET_GPIO_PIN(GPIO_Pin)); // Read current value from ODR register if ((GPIOx->ODR & GPIO_Pin) != 0U) { // If set, clear by writing '0' GPIOx->ODR &= ~GPIO_Pin; } else { // Otherwise, set by writing '1' GPIOx->ODR |= GPIO_Pin; } } ``` This method checks whether the specified bit within `ODR` is already high or low and then writes its inverse back into it[^1]. However, note that direct manipulation like above might not be optimal due to potential race conditions during read-modify-write operations. A more efficient approach involves utilizing another pair of registers specifically designed for setting (`BSRR`) and resetting bits without affecting others simultaneously. But since specific instruction was given about employing only `ODR`, previous implementation adheres strictly thereto while still achieving desired outcome effectively enough under most circumstances when implemented correctly with proper synchronization measures taken as necessary depending upon application requirements. --related questions-- 1. What are other methods besides ODR for toggling GPIO states? 2. How does BSRR work compared to ODR in terms of efficiency and safety? 3. Can you provide examples where direct access to hardware registers becomes essential over library functions? 4. In what scenarios would someone prefer using assembly language instead of C for controlling GPIOs?