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 ------------------------------------------------------------------*/TIM4
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 None
16 * @retval None
17 */
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 None
31 * @retval None
32 */
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 counter
37 clock used is 16 MHz / 128 = 125 000 Hz
38 - 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 ms
40 min time base is 0.016 ms if TIM4_PERIOD = 1 --> ( 1 + 1) / 125000 = 0.016 ms
41 - In this example we need to generate a time base equal to 1 ms
42 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 None
63 */
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 None
74 * @retval None
75 */
76 void TimingDelay_Decrement(void)
77 {
78 if (TimingDelay != 0x00)
79 {
80 TimingDelay--;
81 }
82 }