【实验分享】STM8-SO8-DISCO之第三个工程-AWU唤醒

只看该作者 · 2020-8-10 16:43

AWU是用来当MCU进入低功耗的活跃停机(Active Halt)模式时提供一个内部的唤醒时间基准。该时间基准的时钟是由内部的低速RC振荡器时钟(LSI)或者通过预分频的HSE晶振时钟来提供的。STM8S的LSI时钟测量在使用LSI低速内部时钟时，为了确保最好的精度，它的频率可以通过TIM1_CH1来测定。

1、复制官方AWU工程文件：

2、打开IAR工程，先清除上一工程的编译信息：

3、修改main.c文件：

/* Includes ------------------------------------------------------------------*/
#include "stm8s.h"
#include "main.h"
/**
* @addtogroup AWU_ActiveHaltMode
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
/* Global variables ----------------------------------------------------------*/
bool ButtonPressed = FALSE;
/* Private function prototypes -----------------------------------------------*/
void Delay (uint16_t nCount);
uint32_t LSIMeasurment(void);
static void CLK_Config(void);
void AWU_Config(void);
static void GPIO_Config(void);
/* Private functions ---------------------------------------------------------*/
/**
* @brief Example main entry point.
* @param None
* @retval None
*/
void main(void)
{
uint16_t i = 0;
uint16_t j = 0;
/* 时钟配置 -----------------------------------------*/
CLK_Config();
/* 端口配置 ---------------------------------------*/
GPIO_Config();
/*AWU配置 --------------------------------------------*/
AWU_Config();
/* 使能总中断 */
enableInterrupts();
while (1)
{
/* 按键扫描 */
if (ButtonPressed == TRUE)
{
ButtonPressed = FALSE;
/* LED快速闪烁 */
for (j = 0; j < 20; j++)
{
GPIO_WriteReverse(LEDS_PORT, (GPIO_Pin_TypeDef)LED1_PIN);
for (i = 0; i < 5; i++)
{
Delay((uint16_t)60000);
}
}
/* LED熄灭 */
GPIO_WriteLow(LEDS_PORT,LED1_PIN);
/* 进入停机模式 */
halt();
}
else
{
/* LED慢速闪烁 */
for (i = 0; i < 15; i++)
{
Delay((uint16_t)60000);
}
/* LED反转 */
GPIO_WriteReverse(LEDS_PORT, (GPIO_Pin_TypeDef)LED1_PIN);
}
}
}
/**
* @brief Configure system clock to run at 16Mhz
* @param None
* @retval None
*/
static void CLK_Config(void)
{
/* Initialization of the clock */
/* 配置HSI分频率,CPU分频率1 */
CLK_HSIPrescalerConfig(CLK_PRESCALER_HSIDIV1);
}
/**
* @brief Configure the AWU time base to 12s
* @param None
* @retval None
*/
void AWU_Config(void)
{
/* 初始化 AWU */
/* 通过LSI 校准AWU唤醒时间*/
AWU_LSICalibrationConfig(LSIMeasurment());
/* 停机12S后唤醒 */
AWU_Init(AWU_TIMEBASE_12S);
}
/**
* @brief Configure GPIO for LEDs and buttons available on the evaluation board
* @param None
* @retval None
*/
static void GPIO_Config(void)
{
/* 设置外部中断端口C模式为下降沿触发 */
EXTI_SetExtIntSensitivity(EXTI_PORT_GPIOC, EXTI_SENSITIVITY_FALL_ONLY);
/* 初始化外部中断IO口，悬空输入并使能中断*/
GPIO_Init(BUTTON_PORT, (GPIO_Pin_TypeDef)(BUTTON_PIN), GPIO_MODE_IN_FL_IT);
/* 配置LED1 IO口为输出模式 */
GPIO_Init(LEDS_PORT, (GPIO_Pin_TypeDef)(LED1_PIN), GPIO_MODE_OUT_PP_HIGH_FAST);
}
/**
* @brief Measure the LSI frequency using timer IC1 and update the calibration registers.
* @NOTE It is recommended to use a timer clock frequency of at least 10MHz in order
* to obtain a better in the LSI frequency measurement.
* @param None
* @retval None
*/
uint32_t LSIMeasurment(void)
{
uint32_t lsi_freq_hz = 0x0;
uint32_t fmaster = 0x0;
uint16_t ICValue1 = 0x0;
uint16_t ICValue2 = 0x0;
/* 读取主时钟频率 */
fmaster = CLK_GetClockFreq();
/* 使能 LSI 测量: LSI时钟连接到TIM1_CH1 */
AWU->CSR |= AWU_CSR_MSR;
/* 每8次捕捉一次!!! */
/* 使能TIM1捕捉 */
TIM1_ICInit(TIM1_CHANNEL_1, TIM1_ICPOLARITY_RISING, TIM1_ICSELECTION_DIRECTTI, TIM1_ICPSC_DIV8, 0);
/* 使能 TIM1 */
TIM1_Cmd(ENABLE);
/* 等待 CC1 捕捉 */
while((TIM1->SR1 & TIM1_FLAG_CC1) != TIM1_FLAG_CC1);
/* 读取 CCR1 值*/
ICValue1 = TIM1_GetCapture1();
TIM1_ClearFlag(TIM1_FLAG_CC1);
/* 等待 CC1 捕捉 */
while ((TIM1->SR1 & TIM1_FLAG_CC1) != TIM1_FLAG_CC1);
/* 读取 CCR1 值*/
ICValue2 = TIM1_GetCapture1();
TIM1_ClearFlag(TIM1_FLAG_CC1);
/* 关闭CC1捕捉 */
TIM1->CCER1 &= (uint8_t)(~TIM1_CCER1_CC1E);
/* 关闭TIM1 */
TIM1_Cmd(DISABLE);
/* 计算LSI时钟频率 */
lsi_freq_hz = (8 * fmaster) / (ICValue2 - ICValue1);
/* 禁用LSI测量: LSI时钟从TIM1_CH1断开 */
AWU->CSR &= (uint8_t)(~AWU_CSR_MSR);
/* 返回计算的LSI值 */
return (lsi_freq_hz);
}
/**
* @brief Delay.
* @param nCount
* @retval None
*/
void Delay(uint16_t nCount)
{
/* Decrement nCount value */
while (nCount != 0)
{
nCount--;
}
}