简介：该定时器由一个带可编程预分频器的8位自动重载的向上计数器所组成，它可以用来作为时基发生器，具有溢出中断功能。
主要功能：
（1）8位向上计数的自动重载计数器；
（2）3位可编程的预分配器（可在运行中修改），提供1、2、4、8、16、32、64、128这8种分频比例；
（3）中断产生：更新中断（溢出，计数器初始化）。
代码实现：
1 /* Includes ------------------------------------------------------------------*/ 2 #include "stm8s.h" 3 4 /* Private define ------------------------------------------------------------*/ 5 #define TIM4_PERIOD 124 6 /* Private variables ---------------------------------------------------------*/ 7 __IO uint32_t TimingDelay = 0; 8 /* Private function prototypes -----------------------------------------------*/ 9 void Delay(__IO uint32_t nTime);10 void TimingDelay_Decrement(void);11 static void TIM4_Config(void);12 13 /**14 * @brief Main program.15 * @param None16 * @retval None17 */18 void main(void)19 {20 /* TIM4 configuration -----------------------------------------*/21 TIM4_Config(); 22 23 /* Insert 50 ms delay */24 Delay(50);25 }26 }27 28 /**29 * @brief Configure TIM4 to generate an update interrupt each 1ms 30 * @param None31 * @retval None32 */33 static void TIM4_Config(void)34 {35 /* TIM4 configuration:36 - TIM4CLK is set to 16 MHz, the TIM4 Prescaler is equal to 128 so the TIM1 counter37 clock used is 16 MHz / 128 = 125 000 Hz38 - With 125 000 Hz we can generate time base:39 max time base is 2.048 ms if TIM4_PERIOD = 255 --> (255 + 1) / 125000 = 2.048 ms40 min time base is 0.016 ms if TIM4_PERIOD = 1 --> ( 1 + 1) / 125000 = 0.016 ms41 - In this example we need to generate a time base equal to 1 ms42 so TIM4_PERIOD = (0.001 * 125000 - 1) = 124 */43 44 /* Time base configuration */45 TIM4_TimeBaseInit(TIM4_PRESCALER_128, TIM4_PERIOD);46 /* Clear TIM4 update flag */47 TIM4_ClearFlag(TIM4_FLAG_UPDATE);48 /* Enable update interrupt */49 TIM4_ITConfig(TIM4_IT_UPDATE, ENABLE);50 51 /* enable interrupts */52 enableInterrupts();53 54 /* Enable TIM4 */55 TIM4_Cmd(ENABLE);56 }57 58 59 /**60 * @brief Inserts a delay time.61 * @param nTime: specifies the delay time length, in milliseconds.62 * @retval None63 */64 void Delay(__IO uint32_t nTime)65 {66 TimingDelay = nTime;67 68 while (TimingDelay != 0);69 }70 71 /**72 * @brief Decrements the TimingDelay variable.73 * @param None74 * @retval None75 */76 void TimingDelay_Decrement(void)77 {78 if (TimingDelay != 0x00)79 {80 TimingDelay--;81 }82 }