1 /***************************************************************************//**
2 * @file
3 * @brief Reset Management Unit (RMU) peripheral module peripheral API
4 *
5 * @author Energy Micro AS
6 * @version 3.0.0
7 *******************************************************************************
8 * @section License
9 * <b>(C) Copyright 2012 Energy Micro AS, http://www.energymicro.com</b>
10 *******************************************************************************
11 *
12 * Permission is granted to anyone to use this software for any purpose,
13 * including commercial applications, and to alter it and redistribute it
14 * freely, subject to the following restrictions:
15 *
16 * 1. The origin of this software must not be misrepresented; you must not
17 * claim that you wrote the original software.
18 * 2. Altered source versions must be plainly marked as such, and must not be
19 * misrepresented as being the original software.
20 * 3. This notice may not be removed or altered from any source distribution.
21 *
22 * DISCLAIMER OF WARRANTY/LIMITATION OF REMEDIES: Energy Micro AS has no
23 * obligation to support this Software. Energy Micro AS is providing the
24 * Software "AS IS", with no express or implied warranties of any kind,
25 * including, but not limited to, any implied warranties of merchantability
26 * or fitness for any particular purpose or warranties against infringement
27 * of any proprietary rights of a third party.
28 *
29 * Energy Micro AS will not be liable for any consequential, incidental, or
30 * special damages, or any other relief, or for any claim by any third party,
31 * arising from your use of this Software.
32 *
33 ******************************************************************************/
34 #include "em_rmu.h"
35 #include "em_emu.h"
36 #include "em_bitband.h"
37
38 /***************************************************************************//**
39 * @addtogroup EM_Library
40 * @{
41 ******************************************************************************/
42
43 /***************************************************************************//**
44 * @addtogroup RMU
45 * @brief Reset Management Unit (RMU) Peripheral API
46 * @{
47 ******************************************************************************/
48
49 /*******************************************************************************
50 ************************** GLOBAL FUNCTIONS *******************************
51 ******************************************************************************/
52
53 /***************************************************************************//**
54 * @brief
55 * Disable/enable reset for various peripherals and signal sources
56 *
57 * @param[in] enable
58 * @li false - Disable reset signal or flag
59 * @li true - Enable reset signal or flag
60 ******************************************************************************/
RMU_ResetControl(RMU_Reset_TypeDef reset,bool enable)61 void RMU_ResetControl(RMU_Reset_TypeDef reset, bool enable)
62 {
63 BITBAND_Peripheral(&(RMU->CTRL), (uint32_t)reset, (uint32_t)enable);
64 }
65
66
67 /***************************************************************************//**
68 * @brief
69 * Clear the reset cause register.
70 ******************************************************************************/
RMU_ResetCauseClear(void)71 void RMU_ResetCauseClear(void)
72 {
73 uint32_t locked;
74
75 RMU->CMD = RMU_CMD_RCCLR;
76
77 /* Clear some reset causes not cleared with RMU CMD register */
78 /* (If EMU registers locked, they must be unlocked first) */
79 locked = EMU->LOCK & EMU_LOCK_LOCKKEY_LOCKED;
80 if (locked)
81 {
82 EMU_Unlock();
83 }
84
85 BITBAND_Peripheral(&(EMU->AUXCTRL), 0, 1);
86 BITBAND_Peripheral(&(EMU->AUXCTRL), 0, 0);
87
88 if (locked)
89 {
90 EMU_Lock();
91 }
92 }
93
94
95 /***************************************************************************//**
96 * @brief
97 * Get the cause of the last reset.
98 *
99 * @details
100 * In order to be useful, the reset cause must be cleared by SW before a new
101 * reset occurs, otherwise reset causes may accumulate. See
102 * RMU_ResetCauseClear(). This function call will return the main cause for
103 * reset, which can be a bit mask (several causes), and clear away "noise".
104 *
105 * @return
106 * The reset cause, a bit mask of (typically, but not always, only one) of:
107 * @li RMU_RSTCAUSE_PORST - Power on reset
108 * @li RMU_RSTCAUSE_BODUNREGRST - Brown out detector, unregulated power
109 * @li RMU_RSTCAUSE_BODREGRST - Brown out detector, regulated power
110 * @li RMU_RSTCAUSE_EXTRST - External reset
111 * @li RMU_RSTCAUSE_WDOGRST - Watchdog reset
112 * @li RMU_RSTCAUSE_LOCKUPRST - Cortex-M3 lockup reset
113 * @li RMU_RSTCAUSE_SYSREQRST - Cortex-M3 system request reset
114 * @li RMU_RSTCAUSE_EM4RST - Set if the system has been in EM4
115 * @li RMU_RSTCAUSE_EM4WURST - Set if the system woke up on a pin from EM4
116 * @li RMU_RSTCAUSE_BODAVDD0 - Analog power domain 0 brown out detector reset
117 * @li RMU_RSTCAUSE_BODAVDD1 - Analog power domain 1 brown out detector reset
118 * @li RMU_RSTCAUSE_BUBODVDDDREG - Backup BOD on VDDD_REG triggered
119 * @li RMU_RSTCAUSE_BUBODBUVIN - Backup BOD on BU_VIN triggered
120 * @li RMU_RSTCAUSE_BUBODUNREG - Backup BOD on unregulated power triggered
121 * @li RMU_RSTCAUSE_BUBODREG - Backup BOD on regulated powered has triggered
122 * @li RMU_RSTCAUSE_BUMODERST - System has been in Backup mode
123 ******************************************************************************/
RMU_ResetCauseGet(void)124 uint32_t RMU_ResetCauseGet(void)
125 {
126 uint32_t ret = RMU->RSTCAUSE;
127
128 /* Inspect and decode bits. The decoding must be done in correct order, */
129 /* since some reset causes may trigger other reset causes due to internal */
130 /* design. We are only interested in the main cause. */
131 #if defined(_EFM32_TINY_FAMILY) || defined(_EFM32_GIANT_FAMILY)
132 /* Clear "stray" bits if EM4 bit is set, they will always be active */
133 if (ret & RMU_RSTCAUSE_EM4RST)
134 {
135 ret &= ~(RMU_RSTCAUSE_BODREGRST|
136 RMU_RSTCAUSE_BODUNREGRST|
137 RMU_RSTCAUSE_LOCKUPRST|
138 RMU_RSTCAUSE_SYSREQRST);
139 }
140 #endif
141 if (ret & RMU_RSTCAUSE_PORST)
142 {
143 ret = RMU_RSTCAUSE_PORST;
144 }
145 else if ((ret & 0x83) == RMU_RSTCAUSE_BODUNREGRST)
146 {
147 ret = RMU_RSTCAUSE_BODUNREGRST;
148 }
149 else if ((ret & 0x1f) == RMU_RSTCAUSE_BODREGRST)
150 {
151 ret = RMU_RSTCAUSE_BODREGRST;
152 }
153 /* Both external and watchdog reset may occur at the same time */
154 else if ((ret & 0x1b) & (RMU_RSTCAUSE_EXTRST | RMU_RSTCAUSE_WDOGRST))
155 {
156 ret &= RMU_RSTCAUSE_EXTRST | RMU_RSTCAUSE_WDOGRST;
157 }
158 /* Both lockup and system reset may occur at the same time */
159 else if ((ret & 0x7ff) & (RMU_RSTCAUSE_LOCKUPRST | RMU_RSTCAUSE_SYSREQRST))
160 {
161 ret &= RMU_RSTCAUSE_LOCKUPRST | RMU_RSTCAUSE_SYSREQRST;
162 }
163 /* EM4 wake up and pin retention support */
164 #if defined(_EFM32_TINY_FAMILY) || defined(_EFM32_GIANT_FAMILY)
165 else if (ret & RMU_RSTCAUSE_BODAVDD0)
166 {
167 ret = RMU_RSTCAUSE_BODAVDD0;
168 }
169 else if (ret & RMU_RSTCAUSE_BODAVDD1)
170 {
171 ret = RMU_RSTCAUSE_BODAVDD1;
172 }
173 else if (ret & (RMU_RSTCAUSE_EM4WURST|RMU_RSTCAUSE_EM4RST))
174 {
175 ret &= (RMU_RSTCAUSE_EM4WURST|
176 #if defined(_EFM32_GIANT_FAMILY)
177 RMU_RSTCAUSE_BUMODERST|
178 #endif
179 RMU_RSTCAUSE_EM4RST);
180 }
181 else if (ret & (RMU_RSTCAUSE_EM4RST|RMU_RSTCAUSE_EXTRST))
182 {
183 ret &= (RMU_RSTCAUSE_EM4RST|RMU_RSTCAUSE_EXTRST);
184 }
185 #endif
186 /* Backup power domain support */
187 #if defined(_EFM32_GIANT_FAMILY)
188 else if (ret & (RMU_RSTCAUSE_BUBODVDDDREG))
189 {
190 /* Keep backup mode flag, will only be present in this scenario */
191 ret &= (RMU_RSTCAUSE_BUBODVDDDREG|RMU_RSTCAUSE_BUMODERST);
192 }
193 else if (ret & (RMU_RSTCAUSE_BUBODBUVIN))
194 {
195 ret &= (RMU_RSTCAUSE_BUBODBUVIN);
196 }
197 else if (ret & (RMU_RSTCAUSE_BUBODUNREG))
198 {
199 ret &= (RMU_RSTCAUSE_BUBODUNREG);
200 }
201 else if (ret & (RMU_RSTCAUSE_BUBODREG))
202 {
203 ret &= (RMU_RSTCAUSE_BUBODREG);
204 }
205 #endif
206 else
207 {
208 ret = 0;
209 }
210 return ret;
211 }
212
213
214 /** @} (end addtogroup RMU) */
215 /** @} (end addtogroup EM_Library) */
216