1 /***************************************************************************//**
2 * @file
3 * @brief Voltage Comparator (VCMP) peripheral API
4 * @author Energy Micro AS
5 * @version 3.0.0
6 *******************************************************************************
7 * @section License
8 * <b>(C) Copyright 2012 Energy Micro AS, http://www.energymicro.com</b>
9 *******************************************************************************
10 *
11 * Permission is granted to anyone to use this software for any purpose,
12 * including commercial applications, and to alter it and redistribute it
13 * freely, subject to the following restrictions:
14 *
15 * 1. The origin of this software must not be misrepresented; you must not
16 * claim that you wrote the original software.
17 * 2. Altered source versions must be plainly marked as such, and must not be
18 * misrepresented as being the original software.
19 * 3. This notice may not be removed or altered from any source distribution.
20 *
21 * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
22 * obligation to support this Software. Energy Micro AS is providing the
23 * Software "AS IS", with no express or implied warranties of any kind,
24 * including, but not limited to, any implied warranties of merchantability
25 * or fitness for any particular purpose or warranties against infringement
26 * of any proprietary rights of a third party.
27 *
28 * Energy Micro AS will not be liable for any consequential, incidental, or
29 * special damages, or any other relief, or for any claim by any third party,
30 * arising from your use of this Software.
31 *
32 ******************************************************************************/
33 #include "em_assert.h"
34 #include "em_vcmp.h"
35
36 /***************************************************************************//**
37 * @addtogroup EM_Library
38 * @{
39 ******************************************************************************/
40
41 /***************************************************************************//**
42 * @addtogroup VCMP
43 * @brief Voltage Comparator (VCMP) Peripheral API
44 * @{
45 ******************************************************************************/
46
47 /***************************************************************************//**
48 * @brief
49 * Configure and enable Voltage Comparator
50 *
51 * @param[in] vcmpInit
52 * VCMP Initialization structure
53 ******************************************************************************/
VCMP_Init(const VCMP_Init_TypeDef * vcmpInit)54 void VCMP_Init(const VCMP_Init_TypeDef *vcmpInit)
55 {
56 /* Verify input */
57 EFM_ASSERT((vcmpInit->inactive == 0) || (vcmpInit->inactive == 1));
58 EFM_ASSERT((vcmpInit->biasProg >= 0) && (vcmpInit->biasProg < 16));
59
60 /* Configure Half Bias setting */
61 if (vcmpInit->halfBias)
62 {
63 VCMP->CTRL |= VCMP_CTRL_HALFBIAS;
64 }
65 else
66 {
67 VCMP->CTRL &= ~(VCMP_CTRL_HALFBIAS);
68 }
69
70 /* Configure bias prog */
71 VCMP->CTRL &= ~(_VCMP_CTRL_BIASPROG_MASK);
72 VCMP->CTRL |= (vcmpInit->biasProg << _VCMP_CTRL_BIASPROG_SHIFT);
73
74 /* Configure sense for falling edge */
75 if (vcmpInit->irqFalling)
76 {
77 VCMP->CTRL |= VCMP_CTRL_IFALL;
78 }
79 else
80 {
81 VCMP->CTRL &= ~(VCMP_CTRL_IFALL);
82 }
83
84 /* Configure sense for rising edge */
85 if (vcmpInit->irqRising)
86 {
87 VCMP->CTRL |= VCMP_CTRL_IRISE;
88 }
89 else
90 {
91 VCMP->CTRL &= ~(VCMP_CTRL_IRISE);
92 }
93
94 /* Configure warm-up time */
95 VCMP->CTRL &= ~(_VCMP_CTRL_WARMTIME_MASK);
96 VCMP->CTRL |= (vcmpInit->warmup << _VCMP_CTRL_WARMTIME_SHIFT);
97
98 /* Configure hysteresis */
99 switch (vcmpInit->hyst)
100 {
101 case vcmpHyst20mV:
102 VCMP->CTRL |= VCMP_CTRL_HYSTEN;
103 break;
104 case vcmpHystNone:
105 VCMP->CTRL &= ~(VCMP_CTRL_HYSTEN);
106 break;
107 default:
108 break;
109 }
110
111 /* Configure inactive output value */
112 VCMP->CTRL |= (vcmpInit->inactive << _VCMP_CTRL_INACTVAL_SHIFT);
113
114 /* Configure trigger level */
115 VCMP_TriggerSet(vcmpInit->triggerLevel);
116
117 /* Enable or disable VCMP */
118 if (vcmpInit->enable)
119 {
120 VCMP->CTRL |= VCMP_CTRL_EN;
121 }
122 else
123 {
124 VCMP->CTRL &= ~(VCMP_CTRL_EN);
125 }
126
127 /* If Low Power Reference is enabled, wait until VCMP is ready */
128 /* before enabling it, see reference manual for deatils */
129 /* Configuring Low Power Ref without enable has no effect */
130 if(vcmpInit->lowPowerRef && vcmpInit->enable)
131 {
132 /* Poll for VCMP ready */
133 while(!VCMP_Ready());
134 VCMP_LowPowerRefSet(vcmpInit->lowPowerRef);
135 }
136
137 /* Clear edge interrupt */
138 VCMP_IntClear(VCMP_IF_EDGE);
139 }
140
141
142 /***************************************************************************//**
143 * @brief
144 * Enable or disable Low Power Reference setting
145 *
146 * @param[in] enable
147 * If true, enables low power reference, if false disable low power reference
148 ******************************************************************************/
VCMP_LowPowerRefSet(bool enable)149 void VCMP_LowPowerRefSet(bool enable)
150 {
151 if (enable)
152 {
153 VCMP->INPUTSEL |= VCMP_INPUTSEL_LPREF;
154 }
155 else
156 {
157 VCMP->INPUTSEL &= ~(VCMP_INPUTSEL_LPREF);
158 }
159 }
160
161
162 /***************************************************************************//**
163 * @brief
164 * Configure trigger level of voltage comparator
165 *
166 * @param[in] level
167 * Trigger value, in range 0-63
168 ******************************************************************************/
VCMP_TriggerSet(int level)169 void VCMP_TriggerSet(int level)
170 {
171 /* Trigger range is 6 bits, value from 0-63 */
172 EFM_ASSERT((level > 0) && (level < 64));
173
174 /* Set trigger level */
175 VCMP->INPUTSEL = (VCMP->INPUTSEL & ~(_VCMP_INPUTSEL_TRIGLEVEL_MASK)) |
176 (level << _VCMP_INPUTSEL_TRIGLEVEL_SHIFT);
177 }
178
179
180 /** @} (end addtogroup VCMP) */
181 /** @} (end addtogroup EM_Library) */
182