关于stm32f4上的Timer1的问题

我在avr上进行了长时间的编程后尝试了STM32，我想使用计时器来处理冻结：

HAL_tiM_Base_Start_IT(&htim1);

while ((GPIOA->IDR & GPIO_PIN_3) == 0x08)

{

Clk_h

DWT_Delay(200);

Clk_l

DWT_Delay(200);

}

HAL_TIM_Base_Stop_IT(&htim1);

在上面的代码我等待GPIO_PIN_3将变为低状态。事情是它可能会永远保持高状态，所以我想启动timer1并在500ms之后启动触发中断。问题是while循环捕获0需要大约100us，而我的计时器配置为：

static void MX_TIM1_Init(void)
{
TIM_ClockConfigTypeDef sClockSourceConfig;
TIM_MasterConfigTypeDef sMasterConfig;
htim1.Instance = TIM1;
htim1.Init.Prescaler = 16799;
htim1.Init.CounterMode = TIM_COUNTERMODE_UP;
htim1.Init.Period = 4999;
htim1.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim1.Init.RepetitionCounter = 0;
if (HAL_TIM_Base_Init(&htim1) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim1, &sClockSourceConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim1, &sMasterConfig) != HAL_OK)
{
_Error_Handler(__FILE__, __LINE__);
}
}

所以它远远超过100us，不知道为什么。正如我理解计时器，启动它后，它应该开始计数，当达到该值时，它将触发中断。但即使我立即开始和停止计时器，这里：

HAL_TIM_Base_Start_IT(&htim1);
HAL_TIM_Base_Stop_IT(&htim1);

无论如何它会触发一次。我只需要在计数寄存器溢出时触发中断功能。这是我的溢出函数，它位于stm32f4xx_it.c：

void TIM1_UP_TIM10_IRQHandler(void)
{
/* USER CODE BEGIN TIM1_UP_TIM10_IRQn 0 */
/* USER CODE END TIM1_UP_TIM10_IRQn 0 */
HAL_TIM_IRQHandler(&htim1);
/* USER CODE BEGIN TIM1_UP_TIM10_IRQn 1 */
sprintf(str123,"<>");
CDC_Transmit_FS((uint8_t*)str123,strlen(str123));
/* USER CODE END TIM1_UP_TIM10_IRQn 1 */
}

王燕

2018-9-5 14:57:35

只是一些宏：#define Clk_h HAL_GPIO_WritePin（GPIOA，GPIO_PIN_5，GPIO_PIN_SET）; #define Clk_l HAL_GPIO_WritePin（GPIOA，GPIO_PIN_5，GPIO_PIN_RESET）

李萍

2018-9-5 14:58:09

我没有使用HAL，但预加载了定时器1寄存器，因此你需要发出更新事件以将新值加载到它们中。在HAL中的某个地方（可能是Base_Init？），它将执行此操作，这将导致设置更新中断标志。这就是启用中断时计时器正在激活的原因。在启动定时器/允许中断之前，只需要清除SR寄存器中的UIF（向其写入1 - 在某处执行HAL功能）。

李萍

2018-9-5 14:58:42

此外，如果您来自AVR，我建议不要使用HAL。

我不太习惯用HAL，所以这里是如何通过直接访问定时器外设来做你想做的事情：
// SETUP STUFF:

// Enable the timer clock. I use the HAL for this
// as it adds the required startup delay. The code
// is pretty simple though.
__HAL_RCC_TIM1_CLK_ENABLE();

// Reset the control register. This gives us the
// default operation which is counting up with no
// divider.
TIM1->CR1 = 0;

// Set prescaler
TIM1->PSC = 16799;

// Will generate interrupt when this value is reached
TIM1->ARR = 4999;

// The PSC and ARR values are currently in the preload
// registers. To load them into the active registers we
// need an update event. We can do this manually as
// follows (or we could wait for the timer to expire).
TIM1->EGR |= TIM_EGR_UG;

// Timer is now ready to use.

// POLLING OPERATION:

// Next we setup the interrupts. We should first clear
// the update interrupt flag in case it has already been
// set.
TIM1->SR = ~TIM_SR_UIF;

// Then we can enable the update interrupt source
TIM1->DIER |= TIM_DIER_UIE;

// Note: we also need to setup the interrupt channel on
// the NVIC. Once that is done the isr will fire
// when the timer reaches 5000.

// We can now start the timer running...
TIM1->CR1 |= TIM_CR_CEN;

while ((GPIOA->IDR & GPIO_PIN_3) == 0x08)
{
Clk_h
DWT_Delay(200);
Clk_l
DWT_Delay(200);
}

// ...and stop the timer when we're done
TIM1->CR1 &= ~TIM_CR_CEN;

// Note if we want to repeat the polling loop again we should
// issue another TIM1->EGR |= TIM_EGR_UG event as this
// resets the timer to zero.