1.LPTIM介绍
* n2 h8 F1 J' Y' K% W$ pSTM32L0系列有个LPTIM定时器，即lowpowertimer,低功耗定时器
5 w* r6 ^6 N- U# I

可以看到可供LPTIM使用时钟源分为如下：
' s& S& }# r  J' K内部时钟源：LSE，LSI，HSI或APB时钟
& S) S& N2 ^2 W外部时钟源：LPTIM输入的外部时钟源
ps：如果以LSE，LSI或外部时钟为时钟源时，能够从停止模式唤醒设备。
$ s# _* G- X3 h8 H" Z( x
, Z  a! X' ]- @3 L7 ]本文记录使用LSI为时钟源使用LPTIM

2.配置时钟源并且启动
9 u( o- |+ Y  N' c8 l! H- H9 Z; T

1. /**
   
2.   * @brief System Clock Configuration
   
3.   * @retval None
   
4.   */
   
5. void SystemClock_Config(void)
   
6. {
   , Y% S8 a, j9 C( o( b- U& E" ]
7.   RCC_OscInitTypeDef RCC_OscInitStruct = {0};
   
8.   RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
   4 J% r% a6 W  Y
9.   RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
   & A* q8 z, {# y2 L( r. @5 Y
10. 
    
11.   /** Configure the main internal regulator output voltage
    
12.   */
    
13.   __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
    
14.   /** Initializes the CPU, AHB and APB busses clocks
    3 h& U/ w/ y. U" k2 x: ]' Z! \
15.   */
    
16.   RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_MSI;
    $ y" K2 @( W- @
17.   RCC_OscInitStruct.LSIState = RCC_LSI_ON;
    
18.   RCC_OscInitStruct.MSIState = RCC_MSI_ON;
    
19.   RCC_OscInitStruct.MSICalibrationValue = 0;
    
20.   RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
    
21.   RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
    / x  F$ M3 t, w% A+ \! V$ a
22.   if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    
23.   {
    * |% a! Q/ |, m6 _1 X
24.     Error_Handler();
    2 e3 m. m3 M4 C7 E/ t1 s
25.   }
    
26.   /** Initializes the CPU, AHB and APB busses clocks
    / s' S# P, F3 @( i' z# j4 B# _
27.   */
    
28.   RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
    
29.                               |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
    
30.   RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_MSI;
    
31.   RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    4 F3 M( Y" ~3 I- E2 f& \
32.   RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
    7 b( f) ^4 V$ n! {
33.   RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
    
34. 
    % T5 J) r0 s6 j* u5 ~
35.   if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
    
36.   {
    4 K' E) L$ E0 y1 ~8 K2 }9 v( b
37.     Error_Handler();
    
38.   }
    : B5 e  x# x" k0 O7 t! M
39. 
    
40.     PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC|RCC_PERIPHCLK_LPTIM1;
    
41.     PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
    $ x8 i" N( x4 F8 L5 e
42.     PeriphClkInit.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSI;
    9 K" S/ j" O8 G7 Y2 r
43. 
    2 S% r" ?  P/ l& ?  p: N6 L
44.     if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
    1 y) u% n1 [+ k! C# h7 {" v
45.     {
    $ j. X8 h4 s2 c% Z# H2 @
46.     Error_Handler();
    
47.     }
    
48. }

复制代码

以上是完整的时钟配置函数，使用LPTIM最主要的配置由如下构成：

: F' Z( o3 V% ?

1. RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI;
   
2. RCC_OscInitStruct.LSIState = RCC_LSI_ON;
   ( E  h. Q7 l8 {- L  V  g2 J
3. HAL_RCC_OscConfig(&RCC_OscInitStruct);
   ) Z( l1 T$ f! E3 ]1 Q
4. 
   
5. PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_LPTIM1;
   
6. PeriphClkInit.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSI;
   ' m; n3 `# q$ P' u4 z
7. HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);

复制代码

3.初始化配置LPTIM

1. /**
   
2.   * @brief LPTIM1 Initialization Function
   ) |, |6 ^" c' {2 Y4 h( _
3.   * @param None
   
4.   * @retval None
   $ O  ~" t; }0 \
5.   */
   
6. void MX_LPTIM1_Init(void)  //0.037Mhz  (1+period / 0.037(37000)) = 1s period=36999
   
7. {
   
8.   hlptim1.Instance = LPTIM1;
   
9.   hlptim1.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;
   6 g# N0 e% C& M7 a% [# w
10.   hlptim1.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV1;
    ! h2 T  p3 D0 I
11.   hlptim1.Init.Trigger.Source = LPTIM_TRIGSOURCE_SOFTWARE;
    
12.   hlptim1.Init.OutputPolarity = LPTIM_OUTPUTPOLARITY_HIGH;
    
13.   hlptim1.Init.UpdateMode = LPTIM_UPDATE_IMMEDIATE;
    " O0 L& v2 B6 L, ^# C/ S
14.   hlptim1.Init.CounterSource = LPTIM_COUNTERSOURCE_INTERNAL;
    & e, @0 p1 q) D1 {9 k9 a
15.   if (HAL_LPTIM_Init(&hlptim1) != HAL_OK)
    
16.   {
    2 o; G& [6 D6 M
17.     Error_Handler();
    * F& Q3 D! u. e) K$ q* Z+ v
18.   }
    . s  v8 r+ P6 q- X% P
19. }

复制代码

+ j- H% s5 h8 P& H# b! z4.LPTIM中断处理函数

1. void LPTIM1_IRQHandler(void)
   
2. {
   ' W5 j* E8 W/ G  h) b6 G3 r
3.   HAL_LPTIM_IRQHandler(&hlptim1);
   
4. }

复制代码

5.启用LPTIM，中断触发回调函数
启用LPTIM分为多种方式：如脉冲，PWM，计数等。
( y- i! [$ n# Q+ N% d具体可参考HAL_LPTIM_IRQHandler函数的实现。
% T+ y( x9 G) Y/ z! O3 H& Z* T: n

1. /**
   + J9 @; Z" o, r" q( g  y1 j
2.   * @brief  Handle LPTIM interrupt request.
   
3.   * @param  hlptim LPTIM handle
   
4.   * @retval None
   & X: A: a1 Y2 }) ~: Q
5.   */
   
6. void HAL_LPTIM_IRQHandler(LPTIM_HandleTypeDef *hlptim)
   
7. {
   
8.   /* Compare match interrupt */
   + ^$ K8 C  B9 I& C9 y0 Q) Z
9.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_CMPM) != RESET)
   
10.   {
    
11.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_CMPM) != RESET)
    
12.     {
    
13.       /* Clear Compare match flag */
    
14.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_CMPM);
    6 N, k, w7 m' J# ~. n
15. 
    ; c- o+ \9 p! Q8 e9 ^. e; L8 k
16.       /* Compare match Callback */
    
17. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    
18.       hlptim->CompareMatchCallback(hlptim);
    + }0 r3 l2 u' t; d4 _( i6 o
19. #else
    
20.       HAL_LPTIM_CompareMatchCallback(hlptim);
    
21. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    
22.     }
    % A) W' I8 D# X2 S
23.   }
    
24. 
    ) p, ]4 Q$ I! A0 e* a' H" `, w
25.   /* Autoreload match interrupt */
    
26.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_ARRM) != RESET)
    
27.   {
    
28.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_ARRM) != RESET)
    2 L  b' W/ b! J
29.     {
    
30.       /* Clear Autoreload match flag */
    
31.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_ARRM);
    
32. 
    9 \: J/ [: ?2 \+ ^3 G9 Z7 W
33.       /* Autoreload match Callback */
    
34. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    & e# T, I; _# z4 Y2 `
35.       hlptim->AutoReloadMatchCallback(hlptim);
    9 f' N; Y( A4 S* c& D  G
36. #else
    
37.       HAL_LPTIM_AutoReloadMatchCallback(hlptim);
    , e! V2 R5 }6 v1 F
38. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    
39.     }
    
40.   }
    " }' E) j( v5 F! l3 X  {7 \6 _
41. 
    / V- d2 D1 B7 \
42.   /* Trigger detected interrupt */
    # p" N! V6 P1 m% q! \$ \! l% J
43.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_EXTTRIG) != RESET)
    0 }3 p( {- t0 D" `, K
44.   {
    / K( E6 {( Q# i+ j; i
45.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_EXTTRIG) != RESET)
    
46.     {
    
47.       /* Clear Trigger detected flag */
    
48.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_EXTTRIG);
    2 U3 D( J( n  [5 Z$ ~3 I, T  P
49. 
    
50.       /* Trigger detected callback */
      g. K& O4 g% _" b8 A6 Z: ]
51. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    0 ^! C( q2 t/ }, y4 B
52.       hlptim->TriggerCallback(hlptim);
    
53. #else
    8 l9 v* T. O7 ~! \( ~& v  g+ {
54.       HAL_LPTIM_TriggerCallback(hlptim);
    ! Q- B  {8 ?7 I; r0 }
55. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    
56.     }
    % |8 `7 D) i) s
57.   }
    
58. 
    
59.   /* Compare write interrupt */
    8 |& |3 A7 S, T# z, F# \2 ]' _
60.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_CMPOK) != RESET)
    
61.   {
    
62.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_CMPOK) != RESET)
    ' L3 [) |6 _2 p) D2 i" d
63.     {
    2 V: E+ f2 O5 e/ f7 k! U, L) C6 h
64.       /* Clear Compare write flag */
    
65.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_CMPOK);
    ; ?9 C0 F' k' K
66. 
    # Z1 D  _* a5 g7 f6 X2 U$ ?
67.       /* Compare write Callback */
    
68. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    / h$ ^& |4 u- l4 E2 |" ~
69.       hlptim->CompareWriteCallback(hlptim);
    
70. #else
      b3 y; b! q9 F
71.       HAL_LPTIM_CompareWriteCallback(hlptim);
    # k0 d7 S' a0 _3 i
72. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    ' k  j8 h6 I5 R1 r6 M
73.     }
    / u6 O$ J+ u) m; `& d# I  j
74.   }
    . C% Y. h) `6 i% {
75. 
    & b9 J3 w/ v) U# y- a/ H1 A
76.   /* Autoreload write interrupt */
    
77.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_ARROK) != RESET)
    
78.   {
    ' {) J" _1 w) X
79.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_ARROK) != RESET)
    , {! K% L( ]! v- G& E  G& w, F
80.     {
    * U. F3 o8 t* p' C. a1 ]3 q
81.       /* Clear Autoreload write flag */
    
82.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_ARROK);
    
83. 
    
84.       /* Autoreload write Callback */
    9 L) d* S5 s! M8 C
85. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    * j) Z3 b3 I: C$ ?
86.       hlptim->AutoReloadWriteCallback(hlptim);
    
87. #else
    
88.       HAL_LPTIM_AutoReloadWriteCallback(hlptim);
    - n! j/ Z8 }6 d4 `
89. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    7 a1 D2 z& ?7 R' F, y! |
90.     }
    
91.   }
    
92. 
    
93.   /* Direction counter changed from Down to Up interrupt */
    
94.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_UP) != RESET)
    
95.   {
    
96.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_UP) != RESET)
    ' W. v. [0 z1 I$ u5 J4 k
97.     {
    
98.       /* Clear Direction counter changed from Down to Up flag */
    
99.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_UP);
    
100. 
     % i8 G* F2 s9 f  {
101.       /* Direction counter changed from Down to Up Callback */
     $ |; ^8 B( r, B8 ]
102. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
     
103.       hlptim->DirectionUpCallback(hlptim);
     
104. #else
     4 k7 K  {& J0 c
105.       HAL_LPTIM_DirectionUpCallback(hlptim);
     
106. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
     
107.     }
     ; T3 q2 s$ ^& e* \
108.   }
     
109. 
     ( \! q1 D* @; \) y9 w6 U
110.   /* Direction counter changed from Up to Down interrupt */
     ( P- P5 b5 w; R+ Q" M2 y
111.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_DOWN) != RESET)
     * R$ w% F1 I4 u4 ^! Q9 u" j& P
112.   {
     
113.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_DOWN) != RESET)
     6 |" \4 Q2 L7 b, a0 ^
114.     {
     , y: i6 Z0 A  C+ e- q8 [
115.       /* Clear Direction counter changed from Up to Down flag */
     
116.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_DOWN);
     $ h1 `1 |6 ?4 h4 k; ?. `1 H
117. 
     ( P) D% s1 W5 N- i: y, |1 Q, P3 F
118.       /* Direction counter changed from Up to Down Callback */
     ! I7 M% W" p& P0 U1 p; r
119. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
     
120.       hlptim->DirectionDownCallback(hlptim);
     6 \. E1 R$ X" o! ~/ M
121. #else
     2 q2 O, v3 N: f' |2 t  u, O
122.       HAL_LPTIM_DirectionDownCallback(hlptim);
     6 }  G' `" h7 h0 f9 n  }! N
123. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
     , h- f% s% [' i, i% Q
124.     }
     
125.   }
     
126. }

复制代码

" T; S9 s1 B! m1 q( q* w* U. ]这里示例TimeOut的方式回调。
开启LPTIM定时器需要调用 HAL_LPTIM_TimeOut_Start_IT
" t. F- g+ x+ \( u
' j! h* M/ n$ d

1. //HAL_LPTIM_TimeOut_Start_IT  <=> HAL_LPTIM_CompareMatchCallback
   
2. void HAL_LPTIM_CompareMatchCallback(LPTIM_HandleTypeDef *hlptim)
   
3. {
   
4.     HAL_GPIO_TogglePin(GPIOB,GPIO_PIN_8);
   ) d" N$ h3 E) N6 t3 l$ c& R1 b
5. }

复制代码

9 T: A) F0 o( x6 i: ~6 j) O% a6.main.c 主函数
6 N3 e2 M" ^" r% I/ F

1. int main(void)
   # q8 e4 p/ k" K8 |' s) X! Y
2. {
   
3.     HAL_Init();
   & G9 W3 V, W4 [/ y; n) Y' h
4.     /* Configure the system clock */
   
5.     SystemClock_Config();
   1 M& P7 i, ]& O8 O6 d) U' T
6. 
     y  D  v0 w# Y
7.     MX_LPTIM1_Init();
   $ m1 H+ V2 R2 b0 L  i. t% _
8.     //(1+period / 0.037(37000)) = 1s period=36999  1s触发一次
   
9.     HAL_LPTIM_TimeOut_Start_IT(&hlptim1,36999,1000);
   
10.     while(1){
    , m4 V7 a$ v0 i+ u" D
11.         HAL_Delay(1000);
    2 m- E* W8 _/ i9 O9 \: p' {
12.     }
    

复制代码

* f- X: W% G1 K1 \. `8 m

+ N0 k; \; V3 a7 t" R  l$ F" X  K