在FreeRTOS中需要启用 ARM-Cortex 内核 CYCNT 寄存器。要实现这个功能，必须将地址为0xE0001000的 DWT_CTRL 寄存器的使能位置 1。 我不理解的是为什么要使用下面这种宏定义（第 1 行），把寄存器的值赋值给宏DWT_CTRL，然后像第 34 行那样去修改它？

define DWT_CTRL ((volatile uint32_t)0xE0001000)

int main(void) { / USER CODE BEGIN 1 / TaskHandle_t task1_handle; TaskHandle_t task2_handle;

BaseType_t status;

/ USER CODE END 1 /

/ MCU Configuration--------------------------------------------------------/

/ Reset of all peripherals, Initializes the Flash interface and the Systick. / HAL_Init();

/ USER CODE BEGIN Init /

/ USER CODE END Init /

/ Configure the system clock / SystemClock_Config();

/ USER CODE BEGIN SysInit /

/ USER CODE END SysInit /

/ Initialize all configured peripherals / MX_GPIO_Init(); / USER CODE BEGIN 2 /

//Enable the CYCCNT

DWT_CTRL |= (1<<0);