1 /**
2 ******************************************************************************
3 * @file stm32l0xx_hal_comp_ex.c
4 * @author MCD Application Team
5 * @brief Extended COMP HAL module driver.
6 * @brief This file provides firmware functions to manage voltage reference
7 * VrefInt that must be specifically controlled for comparator
8 * instance COMP2.
9 ******************************************************************************
10 * @attention
11 *
12 * Copyright (c) 2016 STMicroelectronics.
13 * All rights reserved.
14 *
15 * This software is licensed under terms that can be found in the LICENSE file
16 * in the root directory of this software component.
17 * If no LICENSE file comes with this software, it is provided AS-IS.
18 *
19 ******************************************************************************
20 @verbatim
21 ==============================================================================
22 ##### COMP peripheral Extended features #####
23 ==============================================================================
24
25 [..] Comparing to other previous devices, the COMP interface for STM32L0XX
26 devices contains the following additional features
27
28 (+) Possibility to enable or disable the VREFINT which is used as input
29 to the comparator.
30
31
32 @endverbatim
33 ******************************************************************************
34 */
35
36 #if !defined (STM32L010xB) && !defined (STM32L010x8) && !defined (STM32L010x6) && !defined (STM32L010x4)
37 /* Includes ------------------------------------------------------------------*/
38 #include "stm32l0xx_hal.h"
39
40 /** @addtogroup STM32L0xx_HAL_Driver
41 * @{
42 */
43
44 #ifdef HAL_COMP_MODULE_ENABLED
45
46 /** @addtogroup COMPEx
47 * @brief Extended COMP HAL module driver
48 * @{
49 */
50
51 /* Private define ------------------------------------------------------------*/
52 /** @addtogroup COMP_Private_Constants
53 * @{
54 */
55
56 /* Delay for COMP voltage scaler stabilization time (voltage from VrefInt, */
57 /* delay based on VrefInt startup time). */
58 /* Literal set to maximum value (refer to device datasheet, */
59 /* parameter "TVREFINT"). */
60 /* Unit: us */
61 #define COMP_DELAY_VOLTAGE_SCALER_STAB_US (3000U) /*!< Delay for COMP voltage scaler stabilization time */
62
63 /**
64 * @}
65 */
66
67 /* Exported functions --------------------------------------------------------*/
68 /** @addtogroup COMPEx_Exported_Functions
69 * @{
70 */
71
72 /** @addtogroup COMPEx_Exported_Functions_Group1
73 * @brief Extended functions to manage VREFINT for the comparator
74 *
75 * @{
76 */
77
78 /**
79 * @brief Enable Vrefint and path to comparator, used by comparator
80 * instance COMP2 input based on VrefInt or subdivision of VrefInt.
81 * @note The equivalent of this function is managed automatically when
82 * using function "HAL_COMP_Init()".
83 * @note VrefInt requires a startup time
84 * (refer to device datasheet, parameter "TVREFINT").
85 * This function waits for the startup time
86 * (alternative solution: poll for bit SYSCFG_CFGR3_VREFINT_RDYF set).
87 * @note VrefInt must be disabled before entering in low-power mode.
88 * Refer to description of bit EN_VREFINT in reference manual.
89 * @retval None
90 */
HAL_COMPEx_EnableVREFINT(void)91 void HAL_COMPEx_EnableVREFINT(void)
92 {
93 __IO uint32_t wait_loop_index = 0U;
94
95 /* Enable VrefInt voltage reference and buffer */
96 SYSCFG->CFGR3 |= (SYSCFG_CFGR3_ENBUFLP_VREFINT_COMP | SYSCFG_CFGR3_EN_VREFINT);
97
98 /* Wait loop initialization and execution */
99 /* Note: Variable divided by 2 to compensate partially */
100 /* CPU processing cycles. */
101 wait_loop_index = (COMP_DELAY_VOLTAGE_SCALER_STAB_US * (SystemCoreClock / (1000000U * 2U)));
102 while(wait_loop_index != 0U)
103 {
104 wait_loop_index--;
105 }
106 }
107
108 /**
109 * @brief Disable Vrefint and path to comparator, used by comparator
110 * instance COMP2 input based on VrefInt or subdivision of VrefInt.
111 * @note VrefInt must be disabled before entering in low-power mode.
112 * Refer to description of bit EN_VREFINT in reference manual.
113 * @retval None
114 */
HAL_COMPEx_DisableVREFINT(void)115 void HAL_COMPEx_DisableVREFINT(void)
116 {
117 /* Disable VrefInt voltage reference and buffer */
118 SYSCFG->CFGR3 &= (uint32_t)~((uint32_t)(SYSCFG_CFGR3_ENBUFLP_VREFINT_COMP | SYSCFG_CFGR3_EN_VREFINT));
119 }
120
121 /**
122 * @}
123 */
124
125 /**
126 * @}
127 */
128
129 /**
130 * @}
131 */
132
133 #endif /* HAL_COMP_MODULE_ENABLED */
134
135 /**
136 * @}
137 */
138 #endif /* #if !defined (STM32L010xB) && !defined (STM32L010x8) && !defined (STM32L010x6) && !defined (STM32L010x4) */
139
