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Standard C library for AVR-GCC

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sleep.h
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1 /* Copyright (c) 2002, 2004 Theodore A. Roth
2  Copyright (c) 2004, 2007, 2008 Eric B. Weddington
3  Copyright (c) 2005, 2006, 2007 Joerg Wunsch
4  All rights reserved.
5 
6  Redistribution and use in source and binary forms, with or without
7  modification, are permitted provided that the following conditions are met:
8 
9  * Redistributions of source code must retain the above copyright
10  notice, this list of conditions and the following disclaimer.
11 
12  * Redistributions in binary form must reproduce the above copyright
13  notice, this list of conditions and the following disclaimer in
14  the documentation and/or other materials provided with the
15  distribution.
16 
17  * Neither the name of the copyright holders nor the names of
18  contributors may be used to endorse or promote products derived
19  from this software without specific prior written permission.
20 
21  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
22  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
25  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
28  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
29  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
30  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
31  POSSIBILITY OF SUCH DAMAGE. */
32 
33 /* $Id$ */
34 
35 #ifndef _AVR_SLEEP_H_
36 #define _AVR_SLEEP_H_ 1
37 
38 #include <avr/io.h>
39 #include <stdint.h>
40 
41 
42 /** \file */
43 
44 /** \defgroup avr_sleep <avr/sleep.h>: Power Management and Sleep Modes
45 
46  \code #include <avr/sleep.h>\endcode
47 
48  Use of the \c SLEEP instruction can allow an application to reduce its
49  power comsumption considerably. AVR devices can be put into different
50  sleep modes. Refer to the datasheet for the details relating to the device
51  you are using.
52 
53  There are several macros provided in this header file to actually
54  put the device into sleep mode. The simplest way is to optionally
55  set the desired sleep mode using \c set_sleep_mode() (it usually
56  defaults to idle mode where the CPU is put on sleep but all
57  peripheral clocks are still running), and then call
58  \c sleep_mode(). This macro automatically sets the sleep enable bit, goes
59  to sleep, and clears the sleep enable bit.
60 
61  Example:
62  \code
63  #include <avr/sleep.h>
64 
65  ...
66  set_sleep_mode(<mode>);
67  sleep_mode();
68  \endcode
69 
70  Note that unless your purpose is to completely lock the CPU (until a
71  hardware reset), interrupts need to be enabled before going to sleep.
72 
73  As the \c sleep_mode() macro might cause race conditions in some
74  situations, the individual steps of manipulating the sleep enable
75  (SE) bit, and actually issuing the \c SLEEP instruction, are provided
76  in the macros \c sleep_enable(), \c sleep_disable(), and
77  \c sleep_cpu(). This also allows for test-and-sleep scenarios that
78  take care of not missing the interrupt that will awake the device
79  from sleep.
80 
81  Example:
82  \code
83  #include <avr/interrupt.h>
84  #include <avr/sleep.h>
85 
86  ...
87  set_sleep_mode(<mode>);
88  cli();
89  if (some_condition)
90  {
91  sleep_enable();
92  sei();
93  sleep_cpu();
94  sleep_disable();
95  }
96  sei();
97  \endcode
98 
99  This sequence ensures an atomic test of \c some_condition with
100  interrupts being disabled. If the condition is met, sleep mode
101  will be prepared, and the \c SLEEP instruction will be scheduled
102  immediately after an \c SEI instruction. As the intruction right
103  after the \c SEI is guaranteed to be executed before an interrupt
104  could trigger, it is sure the device will really be put to sleep.
105 
106  Some devices have the ability to disable the Brown Out Detector (BOD) before
107  going to sleep. This will also reduce power while sleeping. If the
108  specific AVR device has this ability then an additional macro is defined:
109  \c sleep_bod_disable(). This macro generates inlined assembly code
110  that will correctly implement the timed sequence for disabling the BOD
111  before sleeping. However, there is a limited number of cycles after the
112  BOD has been disabled that the device can be put into sleep mode, otherwise
113  the BOD will not truly be disabled. Recommended practice is to disable
114  the BOD (\c sleep_bod_disable()), set the interrupts (\c sei()), and then
115  put the device to sleep (\c sleep_cpu()), like so:
116 
117  \code
118  #include <avr/interrupt.h>
119  #include <avr/sleep.h>
120 
121  ...
122  set_sleep_mode(<mode>);
123  cli();
124  if (some_condition)
125  {
126  sleep_enable();
127  sleep_bod_disable();
128  sei();
129  sleep_cpu();
130  sleep_disable();
131  }
132  sei();
133  \endcode
134 */
135 
136 
137 /* Define an internal sleep control register and an internal sleep enable bit mask. */
138 #if defined(SLEEP_CTRL)
139 
140  /* XMEGA devices */
141  #define _SLEEP_CONTROL_REG SLEEP_CTRL
142  #define _SLEEP_ENABLE_MASK SLEEP_SEN_bm
143  #define _SLEEP_SMODE_GROUP_MASK SLEEP_SMODE_gm
144 
145 #elif defined(SLPCTRL)
146 
147  /* New xmega devices */
148  #define _SLEEP_CONTROL_REG SLPCTRL_CTRLA
149  #define _SLEEP_ENABLE_MASK SLPCTRL_SEN_bm
150  #define _SLEEP_SMODE_GROUP_MASK SLPCTRL_SMODE_gm
151 
152 #elif defined(SMCR)
153 
154  #define _SLEEP_CONTROL_REG SMCR
155  #define _SLEEP_ENABLE_MASK _BV(SE)
156 
157 #elif defined(__AVR_AT94K__)
158 
159  #define _SLEEP_CONTROL_REG MCUR
160  #define _SLEEP_ENABLE_MASK _BV(SE)
161 
162 #elif !defined(__DOXYGEN__)
163 
164  #define _SLEEP_CONTROL_REG MCUCR
165  #define _SLEEP_ENABLE_MASK _BV(SE)
166 
167 #endif
168 
169 
170 /* Special casing these three devices - they are the
171  only ones that need to write to more than one register. */
172 #if defined(__AVR_ATmega161__)
173 
174  #define set_sleep_mode(mode) \
175  do { \
176  MCUCR = ((MCUCR & ~_BV(SM1)) | ((mode) == SLEEP_MODE_PWR_DOWN || (mode) == SLEEP_MODE_PWR_SAVE ? _BV(SM1) : 0)); \
177  EMCUCR = ((EMCUCR & ~_BV(SM0)) | ((mode) == SLEEP_MODE_PWR_SAVE ? _BV(SM0) : 0)); \
178  } while(0)
179 
180 
181 #elif defined(__AVR_ATmega162__) \
182 || defined(__AVR_ATmega8515__)
183 
184  #define set_sleep_mode(mode) \
185  do { \
186  MCUCR = ((MCUCR & ~_BV(SM1)) | ((mode) == SLEEP_MODE_IDLE ? 0 : _BV(SM1))); \
187  MCUCSR = ((MCUCSR & ~_BV(SM2)) | ((mode) == SLEEP_MODE_STANDBY || (mode) == SLEEP_MODE_EXT_STANDBY ? _BV(SM2) : 0)); \
188  EMCUCR = ((EMCUCR & ~_BV(SM0)) | ((mode) == SLEEP_MODE_PWR_SAVE || (mode) == SLEEP_MODE_EXT_STANDBY ? _BV(SM0) : 0)); \
189  } while(0)
190 
191 /* For xmegas, check presence of SLEEP_SMODE<n>_bm and define set_sleep_mode accordingly. */
192 #elif defined(__AVR_XMEGA__)
193 
194 #define set_sleep_mode(mode) \
195  do { \
196  _SLEEP_CONTROL_REG = ((_SLEEP_CONTROL_REG & ~(_SLEEP_SMODE_GROUP_MASK)) | (mode)); \
197  } while(0)
198 
199 /* For everything else, check for presence of SM<n> and define set_sleep_mode accordingly. */
200 #else
201 #if defined(SM2)
202 
203  #define set_sleep_mode(mode) \
204  do { \
205  _SLEEP_CONTROL_REG = ((_SLEEP_CONTROL_REG & ~(_BV(SM0) | _BV(SM1) | _BV(SM2))) | (mode)); \
206  } while(0)
207 
208 #elif defined(SM1)
209 
210  #define set_sleep_mode(mode) \
211  do { \
212  _SLEEP_CONTROL_REG = ((_SLEEP_CONTROL_REG & ~(_BV(SM0) | _BV(SM1))) | (mode)); \
213  } while(0)
214 
215 #elif defined(SM)
216 
217  #define set_sleep_mode(mode) \
218  do { \
219  _SLEEP_CONTROL_REG = ((_SLEEP_CONTROL_REG & ~_BV(SM)) | (mode)); \
220  } while(0)
221 
222 #else
223 
224  #error "No SLEEP mode defined for this device."
225 
226 #endif /* if defined(SM2) */
227 #endif /* #if defined(__AVR_ATmega161__) */
228 
229 
230 
231 /** \ingroup avr_sleep
232 
233  Put the device in sleep mode. How the device is brought out of sleep mode
234  depends on the specific mode selected with the set_sleep_mode() function.
235  See the data sheet for your device for more details. */
236 
237 
238 #if defined(__DOXYGEN__)
239 
240 /** \ingroup avr_sleep
241 
242  Set the SE (sleep enable) bit.
243 */
244 extern void sleep_enable (void);
245 
246 #else
247 
248 #define sleep_enable() \
249 do { \
250  _SLEEP_CONTROL_REG |= (uint8_t)_SLEEP_ENABLE_MASK; \
251 } while(0)
252 
253 #endif
254 
255 
256 #if defined(__DOXYGEN__)
257 
258 /** \ingroup avr_sleep
259 
260  Clear the SE (sleep enable) bit.
261 */
262 extern void sleep_disable (void);
263 
264 #else
265 
266 #define sleep_disable() \
267 do { \
268  _SLEEP_CONTROL_REG &= (uint8_t)(~_SLEEP_ENABLE_MASK); \
269 } while(0)
270 
271 #endif
272 
273 
274 /** \ingroup avr_sleep
275 
276  Put the device into sleep mode. The SE bit must be set
277  beforehand, and it is recommended to clear it afterwards.
278 */
279 #if defined(__DOXYGEN__)
280 
281 extern void sleep_cpu (void);
282 
283 #else
284 
285 #define sleep_cpu() \
286 do { \
287  __asm__ __volatile__ ( "sleep" "\n\t" :: ); \
288 } while(0)
289 
290 #endif
291 
292 
293 #if defined(__DOXYGEN__)
294 
295 /** \ingroup avr_sleep
296 
297  Put the device into sleep mode, taking care of setting
298  the SE bit before, and clearing it afterwards. */
299 extern void sleep_mode (void);
300 
301 #else
302 
303 #define sleep_mode() \
304 do { \
305  sleep_enable(); \
306  sleep_cpu(); \
307  sleep_disable(); \
308 } while (0)
309 
310 #endif
311 
312 
313 #if defined(__DOXYGEN__)
314 
315 /** \ingroup avr_sleep
316 
317  Disable BOD before going to sleep.
318  Not available on all devices.
319 */
320 extern void sleep_bod_disable (void);
321 
322 #else
323 
324 #if defined(BODS) && defined(BODSE)
325 
326 #ifdef BODCR
327 
328 #define BOD_CONTROL_REG BODCR
329 
330 #else
331 
332 #define BOD_CONTROL_REG MCUCR
333 
334 #endif
335 
336 #define sleep_bod_disable() \
337 do { \
338  uint8_t tempreg; \
339  __asm__ __volatile__("in %[tempreg], %[mcucr]" "\n\t" \
340  "ori %[tempreg], %[bods_bodse]" "\n\t" \
341  "out %[mcucr], %[tempreg]" "\n\t" \
342  "andi %[tempreg], %[not_bodse]" "\n\t" \
343  "out %[mcucr], %[tempreg]" \
344  : [tempreg] "=&d" (tempreg) \
345  : [mcucr] "I" _SFR_IO_ADDR(BOD_CONTROL_REG), \
346  [bods_bodse] "i" (_BV(BODS) | _BV(BODSE)), \
347  [not_bodse] "i" (~_BV(BODSE))); \
348 } while (0)
349 
350 #endif
351 
352 #endif
353 
354 
355 /*@}*/
356 
357 #endif /* _AVR_SLEEP_H_ */
sleep_enable
void sleep_enable(void)
sleep_mode
void sleep_mode(void)
sleep_bod_disable
void sleep_bod_disable(void)
sleep_disable
void sleep_disable(void)
sleep_cpu
void sleep_cpu(void)
stdint.h
io.h