1.LPTIM介绍
STM32L0系列有个LPTIM定时器，即lowpowertimer,低功耗定时器
% d; Y3 w' B6 Q( m7 X9 u5 J

& v9 Y. T/ h8 c4 z可以看到可供LPTIM使用时钟源分为如下：
内部时钟源：LSE，LSI，HSI或APB时钟
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。
& i5 m/ h" I. X! d! x5 W9 Y; ^
( p& e2 H) \  b7 p$ k- R本文记录使用LSI为时钟源使用LPTIM
3 N7 E. Q$ `$ t$ k3 e8 B- m2 \* `
$ J3 h* N6 i4 w$ Q% _2.配置时钟源并且启动
# g9 w6 h; c) s; l! v

1. /**
   ) P. _9 H, r, n' ?; G& Q
2.   * @brief System Clock Configuration
   
3.   * @retval None
   : s* W% N- t- a6 K) Q" h
4.   */
   . f0 V/ J/ n2 ]" W( b7 k
5. void SystemClock_Config(void)
   " G  i% T; H6 p2 `+ g# |) x. S% Z
6. {
   1 G1 p! ~  p( w/ g: X. p
7.   RCC_OscInitTypeDef RCC_OscInitStruct = {0};
   
8.   RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
   $ N( D9 z; D' x
9.   RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
   - d* f; z) k) C) O% j
10. 
    
11.   /** Configure the main internal regulator output voltage
    
12.   */
    9 g* m; W) o4 m2 V& e8 H
13.   __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
    
14.   /** Initializes the CPU, AHB and APB busses clocks
    
15.   */
    : b  I' ?$ [) ^" b* d
16.   RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_MSI;
    * Y- ^% j) H. \- v8 M
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;
    2 O4 P, Q( f+ q5 J
22.   if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
    * s* t# T8 _7 y7 j
23.   {
    2 N9 t9 Y! w7 M$ o. p: ]1 H
24.     Error_Handler();
    6 _. @/ n; Z  E8 T
25.   }
    
26.   /** Initializes the CPU, AHB and APB busses clocks
    
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;
    3 s' R2 H0 f0 c0 D1 k  H
31.   RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
    
32.   RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
    
33.   RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
    # \1 K4 f2 q: b: V, ]; V
34. 
    
35.   if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
    ( e# h+ u9 f$ j$ W
36.   {
    / N% h) J! |! e- N7 m
37.     Error_Handler();
    
38.   }
    ; e. o' O- [! w1 K( S- @5 S3 M7 n
39. 
    4 |0 p- }7 H2 S& x1 r6 F1 C
40.     PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC|RCC_PERIPHCLK_LPTIM1;
    
41.     PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
    
42.     PeriphClkInit.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSI;
    * N1 G( r5 I, t9 }. k
43. 
    , Z# z- X8 S1 l, p' X
44.     if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
    
45.     {
    
46.     Error_Handler();
    1 u4 c: ]- R; G
47.     }
    
48. }

复制代码

/ p1 q; D3 e+ m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：

1. RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI;
   
2. RCC_OscInitStruct.LSIState = RCC_LSI_ON;
   
3. HAL_RCC_OscConfig(&RCC_OscInitStruct);
   ; H4 q2 h$ U* z$ G
4. 
   % ~( u3 M6 O+ g9 c3 f) t1 F
5. PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_LPTIM1;
   + o0 O1 Z+ z5 I0 j) T% {& f
6. PeriphClkInit.LptimClockSelection = RCC_LPTIM1CLKSOURCE_LSI;
   
7. HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit);

复制代码

3.初始化配置LPTIM
( M  G* }2 ^8 T8 U; E% w( N3 W

1. /**
   
2.   * @brief LPTIM1 Initialization Function
   
3.   * @param None
   
4.   * @retval None
   
5.   */
   
6. void MX_LPTIM1_Init(void)  //0.037Mhz  (1+period / 0.037(37000)) = 1s period=36999
   
7. {
   
8.   hlptim1.Instance = LPTIM1;
   . l% F1 m: A( S# ?+ T
9.   hlptim1.Init.Clock.Source = LPTIM_CLOCKSOURCE_APBCLOCK_LPOSC;
   ' D/ J7 B& v: P0 A' L4 E9 W$ y
10.   hlptim1.Init.Clock.Prescaler = LPTIM_PRESCALER_DIV1;
    
11.   hlptim1.Init.Trigger.Source = LPTIM_TRIGSOURCE_SOFTWARE;
    
12.   hlptim1.Init.OutputPolarity = LPTIM_OUTPUTPOLARITY_HIGH;
    + q; d( h, [7 {# f! M
13.   hlptim1.Init.UpdateMode = LPTIM_UPDATE_IMMEDIATE;
    
14.   hlptim1.Init.CounterSource = LPTIM_COUNTERSOURCE_INTERNAL;
    
15.   if (HAL_LPTIM_Init(&hlptim1) != HAL_OK)
    
16.   {
    9 n: r4 w4 P7 C
17.     Error_Handler();
    
18.   }
    
19. }

复制代码

* q: `, U% L5 [% Y& b4.LPTIM中断处理函数
/ T2 }1 u, n; N9 |: O2 }* H

1. void LPTIM1_IRQHandler(void)
   
2. {
   : z& x& R5 t2 J. a7 e- \' w8 K
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。
* z% C; n) T) r0 [8 F9 ?具体可参考HAL_LPTIM_IRQHandler函数的实现。

. w# ^) M: f7 ^* a+ n' v+ {

1. /**
   ' X" P' o# H. r) g2 t
2.   * @brief  Handle LPTIM interrupt request.
   + M8 ]6 v# Y* y3 z4 c8 D
3.   * @param  hlptim LPTIM handle
   
4.   * @retval None
   ! ^: [6 }: C7 @) W6 q  l
5.   */
   9 O' ^% E5 n1 A/ {# ]
6. void HAL_LPTIM_IRQHandler(LPTIM_HandleTypeDef *hlptim)
   1 ~& v. X. I1 D7 s
7. {
   
8.   /* Compare match interrupt */
   
9.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_CMPM) != RESET)
   1 ^4 L& T- m+ v4 `, x7 ?9 R
10.   {
    
11.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_CMPM) != RESET)
    
12.     {
    9 L. `6 D, X4 F) Y/ ^; h" @
13.       /* Clear Compare match flag */
    
14.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_CMPM);
    
15. 
    
16.       /* Compare match Callback */
    ( p. S5 b: w! k9 i9 V7 }5 ]: `- m
17. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    
18.       hlptim->CompareMatchCallback(hlptim);
    1 q: l# }8 j1 B- B& z( }8 D6 o; |
19. #else
    
20.       HAL_LPTIM_CompareMatchCallback(hlptim);
    ' G: O3 L) N& o1 _# w
21. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    0 s- T9 o& C! M9 s' N. `
22.     }
    . p* v+ b5 E8 u$ X1 j6 ]
23.   }
    * o* o3 p$ u# q
24. 
    
25.   /* Autoreload match interrupt */
    - ?8 V" S5 t( A) s
26.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_ARRM) != RESET)
    
27.   {
    ( n7 G) y; ~# N* D3 [6 V
28.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_ARRM) != RESET)
    9 s4 }- J0 Z% v$ i" N
29.     {
    , |; u2 J. T: A8 k# Q* [, d3 C+ _
30.       /* Clear Autoreload match flag */
    6 G# Y0 v, F0 s& E+ ^  P
31.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_ARRM);
    5 b0 E3 P: y( s4 _; c( C
32. 
    
33.       /* Autoreload match Callback */
    5 v! `* m( D1 j4 r0 l* v8 r1 K
34. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    / \$ O% m  d9 b! o2 N9 E
35.       hlptim->AutoReloadMatchCallback(hlptim);
    
36. #else
    
37.       HAL_LPTIM_AutoReloadMatchCallback(hlptim);
    
38. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    
39.     }
    
40.   }
    
41. 
    ! g* G# ~0 Z, i! K
42.   /* Trigger detected interrupt */
    
43.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_EXTTRIG) != RESET)
    & K) n% c" V& N& w) T
44.   {
    " b1 o8 r6 t& t8 N3 }
45.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_EXTTRIG) != RESET)
    
46.     {
    
47.       /* Clear Trigger detected flag */
    9 y; L  X2 C. ?8 ^( F' R$ q
48.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_EXTTRIG);
    2 j+ @, Y# {& w& q# e
49. 
    5 A  L/ g' |  l, o" W. e3 C$ B
50.       /* Trigger detected callback */
    
51. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    
52.       hlptim->TriggerCallback(hlptim);
    
53. #else
    
54.       HAL_LPTIM_TriggerCallback(hlptim);
    , n4 I% w! }( F' A/ X
55. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    
56.     }
    
57.   }
    2 _# d9 i* u% D; H
58. 
    
59.   /* Compare write interrupt */
    
60.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_CMPOK) != RESET)
    ( q; C! S8 \$ r$ \! M) O/ e
61.   {
    ' j6 f! _2 x/ w7 \
62.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_CMPOK) != RESET)
    
63.     {
    
64.       /* Clear Compare write flag */
    
65.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_CMPOK);
    
66. 
    ) H1 K3 W1 D  O5 q" N9 P; D
67.       /* Compare write Callback */
    
68. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    4 k0 S" K8 U+ R; g/ F% q. g
69.       hlptim->CompareWriteCallback(hlptim);
    
70. #else
    
71.       HAL_LPTIM_CompareWriteCallback(hlptim);
    
72. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    
73.     }
    
74.   }
    ) D* S1 F) f( o- g0 C. S4 \
75. 
    1 o# q/ r( N& x
76.   /* Autoreload write interrupt */
    
77.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_ARROK) != RESET)
    3 ~! H$ ^) u$ V( e9 _# X: y
78.   {
    ; Y0 ^3 a) u# P/ @
79.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_ARROK) != RESET)
    7 n4 ^0 e! z& D' {) P0 E
80.     {
    9 Z0 S6 z* n% Z; `4 R8 o
81.       /* Clear Autoreload write flag */
    
82.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_ARROK);
    / \( p) u+ r# u% H) z
83. 
    : F! d5 {& c9 [) b7 D" d
84.       /* Autoreload write Callback */
    ; Y/ C& v4 V2 C) E- c' i: k# e
85. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
    " r* B/ O5 D; T; b  `8 w
86.       hlptim->AutoReloadWriteCallback(hlptim);
    / U$ q$ {0 L! s/ o
87. #else
    
88.       HAL_LPTIM_AutoReloadWriteCallback(hlptim);
    
89. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
    
90.     }
    ( p1 o+ B! z$ L% O* {6 C
91.   }
    
92. 
    + f0 u. M; H6 S  q- t! [1 L5 ~
93.   /* Direction counter changed from Down to Up interrupt */
    4 ]5 P' G; ]' B( W, G
94.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_UP) != RESET)
    
95.   {
    
96.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_UP) != RESET)
    
97.     {
    3 {( F9 A. q: w+ O
98.       /* Clear Direction counter changed from Down to Up flag */
    
99.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_UP);
    ) _  N* J3 x4 Y
100. 
     
101.       /* Direction counter changed from Down to Up Callback */
     9 \2 P1 A: J! L! j) K7 j
102. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
     
103.       hlptim->DirectionUpCallback(hlptim);
     ' x" O0 @* J* @4 w! y: I' m2 o% ~6 X
104. #else
     
105.       HAL_LPTIM_DirectionUpCallback(hlptim);
     ) |" H" {* ~( `9 w+ B
106. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
     ) \% Z0 b7 {! T$ u8 [+ w$ h
107.     }
     
108.   }
     1 D1 m! b+ h: {2 u
109. 
     9 L( l, |* C) m! E' `6 O
110.   /* Direction counter changed from Up to Down interrupt */
     
111.   if (__HAL_LPTIM_GET_FLAG(hlptim, LPTIM_FLAG_DOWN) != RESET)
     
112.   {
     
113.     if (__HAL_LPTIM_GET_IT_SOURCE(hlptim, LPTIM_IT_DOWN) != RESET)
     
114.     {
     9 q& E: X4 M$ i& [# `( U! P2 X- ~* w
115.       /* Clear Direction counter changed from Up to Down flag */
     
116.       __HAL_LPTIM_CLEAR_FLAG(hlptim, LPTIM_FLAG_DOWN);
     
117. 
     
118.       /* Direction counter changed from Up to Down Callback */
     2 g+ J) o9 p  O, M& J
119. #if (USE_HAL_LPTIM_REGISTER_CALLBACKS == 1)
     3 q6 ]( x! u0 Z# @; y! u0 n$ f7 v
120.       hlptim->DirectionDownCallback(hlptim);
     
121. #else
     9 ?: u- C( N5 G( h( ?
122.       HAL_LPTIM_DirectionDownCallback(hlptim);
     ( X$ ]6 L2 e- m5 ]: }8 W
123. #endif /* USE_HAL_LPTIM_REGISTER_CALLBACKS */
     $ M6 q! Y5 j, t
124.     }
     ' S- |- r7 ^6 S5 O
125.   }
     
126. }

复制代码

" x4 @# P7 d  C- R" v) Y) |这里示例TimeOut的方式回调。
: K# Z: P  h4 S. Z开启LPTIM定时器需要调用 HAL_LPTIM_TimeOut_Start_IT

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);
   
5. }

复制代码

+ y  ?7 J: P# h2 Z6.main.c 主函数
% N+ Y+ R: B- s6 y6 ?

1. int main(void)
   
2. {
   
3.     HAL_Init();
   8 v$ Z. d/ M) |& m
4.     /* Configure the system clock */
   $ V0 ]" G9 I* Q; K
5.     SystemClock_Config();
   ; ~* b/ b7 i' b$ R+ O, }
6. 
   3 `1 _4 N/ J' M- r; Z
7.     MX_LPTIM1_Init();
   
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){
    
11.         HAL_Delay(1000);
    ! G+ Y) f6 W2 U
12.     }
    

复制代码

3 _' Y8 A  c( N2 x
3 i4 l' a# s5 t9 o5 b
' F/ r! p: c4 c; B' L