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 controled for comparator
8 * instance COMP2.
9 @verbatim
10 ==============================================================================
11 ##### COMP peripheral Extended features #####
12 ==============================================================================
13
14 [..] Comparing to other previous devices, the COMP interface for STM32L0XX
15 devices contains the following additional features
16
17 (+) Possibility to enable or disable the VREFINT which is used as input
18 to the comparator.
19
20
21 @endverbatim
22 ******************************************************************************
23 * @attention
24 *
25 * <h2><center>© COPYRIGHT(c) 2016 STMicroelectronics</center></h2>
26 *
27 * Redistribution and use in source and binary forms, with or without modification,
28 * are permitted provided that the following conditions are met:
29 * 1. Redistributions of source code must retain the above copyright notice,
30 * this list of conditions and the following disclaimer.
31 * 2. Redistributions in binary form must reproduce the above copyright notice,
32 * this list of conditions and the following disclaimer in the documentation
33 * and/or other materials provided with the distribution.
34 * 3. Neither the name of STMicroelectronics nor the names of its contributors
35 * may be used to endorse or promote products derived from this software
36 * without specific prior written permission.
37 *
38 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
39 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
41 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
42 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
43 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
44 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
45 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
46 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
47 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
48 *
49 ******************************************************************************
50 */
51
52 /* Includes ------------------------------------------------------------------*/
53 #include "stm32l0xx_hal.h"
54
55 /** @addtogroup STM32L0xx_HAL_Driver
56 * @{
57 */
58
59 #ifdef HAL_COMP_MODULE_ENABLED
60
61 /** @addtogroup COMPEx
62 * @brief Extended COMP HAL module driver
63 * @{
64 */
65
66 /* Private define ------------------------------------------------------------*/
67 /** @addtogroup COMP_Private_Constants
68 * @{
69 */
70
71 /* Delay for COMP voltage scaler stabilization time (voltage from VrefInt, */
72 /* delay based on VrefInt startup time). */
73 /* Literal set to maximum value (refer to device datasheet, */
74 /* parameter "TVREFINT"). */
75 /* Unit: us */
76 #define COMP_DELAY_VOLTAGE_SCALER_STAB_US ((uint32_t)3000U) /*!< Delay for COMP voltage scaler stabilization time */
77
78 /**
79 * @}
80 */
81
82 /* Exported functions --------------------------------------------------------*/
83 /** @addtogroup COMPEx_Exported_Functions
84 * @{
85 */
86
87 /** @addtogroup COMPEx_Exported_Functions_Group1
88 * @brief Extended functions to manage VREFINT for the comparator
89 *
90 * @{
91 */
92
93 /**
94 * @brief Enable Vrefint and path to comparator, used by comparator
95 * instance COMP2 input based on VrefInt or subdivision of VrefInt.
96 * @note The equivalent of this function is managed automatically when
97 * using function "HAL_COMP_Init()".
98 * @note VrefInt requires a startup time
99 * (refer to device datasheet, parameter "TVREFINT").
100 * This function waits for the startup time
101 * (alternative solution: poll for bit SYSCFG_CFGR3_VREFINT_RDYF set).
102 * @retval None
103 */
HAL_COMPEx_EnableVREFINT(void)104 void HAL_COMPEx_EnableVREFINT(void)
105 {
106 __IO uint32_t wait_loop_index = 0U;
107
108 /* Enable the Buffer for the COMP by setting ENBUFLP_VREFINT_COMP bit in the CFGR3 register */
109 SYSCFG->CFGR3 |= (SYSCFG_CFGR3_ENBUFLP_VREFINT_COMP);
110
111 /* Wait loop initialization and execution */
112 /* Note: Variable divided by 2 to compensate partially */
113 /* CPU processing cycles. */
114 wait_loop_index = (COMP_DELAY_VOLTAGE_SCALER_STAB_US * (SystemCoreClock / (1000000U * 2U)));
115 while(wait_loop_index != 0U)
116 {
117 wait_loop_index--;
118 }
119 }
120
121 /**
122 * @brief Disable Vrefint and path to comparator, used by comparator
123 * instance COMP2 input based on VrefInt or subdivision of VrefInt.
124 * @retval None
125 */
HAL_COMPEx_DisableVREFINT(void)126 void HAL_COMPEx_DisableVREFINT(void)
127 {
128 /* Disable the Vrefint by resetting ENBUFLP_VREFINT_COMP bit in the CFGR3 register */
129 SYSCFG->CFGR3 &= (uint32_t)~((uint32_t)(SYSCFG_CFGR3_ENBUFLP_VREFINT_COMP));
130 }
131
132 /**
133 * @}
134 */
135
136 /**
137 * @}
138 */
139
140 /**
141 * @}
142 */
143
144 #endif /* HAL_COMP_MODULE_ENABLED */
145
146 /**
147 * @}
148 */
149 /************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/
150
