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eeprom.h

00001 /* Copyright (c) 2002, 2003, 2004, 2007 Marek Michalkiewicz
00002    Copyright (c) 2005, 2006 Bjoern Haase
00003    Copyright (c) 2008 Atmel Corporation
00004    Copyright (c) 2008 Wouter van Gulik
00005    Copyright (c) 2009 Dmitry Xmelkov
00006    All rights reserved.
00007 
00008    Redistribution and use in source and binary forms, with or without
00009    modification, are permitted provided that the following conditions are met:
00010 
00011    * Redistributions of source code must retain the above copyright
00012      notice, this list of conditions and the following disclaimer.
00013    * Redistributions in binary form must reproduce the above copyright
00014      notice, this list of conditions and the following disclaimer in
00015      the documentation and/or other materials provided with the
00016      distribution.
00017    * Neither the name of the copyright holders nor the names of
00018      contributors may be used to endorse or promote products derived
00019      from this software without specific prior written permission.
00020 
00021   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
00022   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
00023   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
00024   ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
00025   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
00026   CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
00027   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
00028   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
00029   CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
00030   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
00031   POSSIBILITY OF SUCH DAMAGE. */
00032 
00033 /* $Id$ */
00034 
00035 #ifndef _AVR_EEPROM_H_
00036 #define _AVR_EEPROM_H_ 1
00037 
00038 #include <avr/io.h>
00039 
00040 #if !E2END && !defined(__DOXYGEN__) && !defined(__COMPILING_AVR_LIBC__)
00041 # warning "Device does not have EEPROM available."
00042 #else
00043 
00044 #if defined (EEAR) && !defined (EEARL) && !defined (EEARH)
00045 #define EEARL EEAR
00046 #endif
00047 
00048 #if (EEPROM_PAGE_SIZE == 1)
00049 /* True for Dx devices right now, can write directly
00050    to mapped EEPROM mem by just setting mode to
00051    EEERWR, writing bytes and then clearing mode. */
00052 #define __EEPROM_NON_PAGE_WRITE_AVAILABLE__ 1
00053 #endif
00054 
00055 #ifndef __ASSEMBLER__
00056 
00057 #include <stddef.h> /* size_t */
00058 #include <stdint.h>
00059 
00060 /** \defgroup avr_eeprom <avr/eeprom.h>: EEPROM handling
00061     \code #include <avr/eeprom.h> \endcode
00062 
00063     This header file declares the interface to some simple library
00064     routines suitable for handling the data EEPROM contained in the
00065     AVR microcontrollers.  The implementation uses a simple polled
00066     mode interface.  Applications that require interrupt-controlled
00067     EEPROM access to ensure that no time will be wasted in spinloops
00068     will have to deploy their own implementation.
00069 
00070     \par Notes:
00071 
00072     - In addition to the write functions there is a set of update ones.
00073     This functions read each byte first and skip the burning if the
00074     old value is the same with new.  The scaning direction is from
00075     high address to low, to obtain quick return in common cases.
00076 
00077     - All of the read/write functions first make sure the EEPROM is
00078     ready to be accessed.  Since this may cause long delays if a
00079     write operation is still pending, time-critical applications
00080     should first poll the EEPROM e. g. using eeprom_is_ready() before
00081     attempting any actual I/O.  But this functions are not wait until
00082     SELFPRGEN in SPMCSR becomes zero.  Do this manually, if your
00083     softwate contains the Flash burning.
00084 
00085     - As these functions modify IO registers, they are known to be
00086     non-reentrant.  If any of these functions are used from both,
00087     standard and interrupt context, the applications must ensure
00088     proper protection (e.g. by disabling interrupts before accessing
00089     them).
00090 
00091     - All write functions force erase_and_write programming mode.
00092     
00093     - For Xmega the EEPROM start address is 0, like other architectures.
00094     The reading functions add the 0x2000 value to use EEPROM mapping into
00095     data space.
00096  */
00097 
00098 #ifdef __cplusplus
00099 extern "C" {
00100 #endif
00101 
00102 #ifndef __ATTR_PURE__
00103 # ifdef  __DOXYGEN__
00104 #  define __ATTR_PURE__
00105 # else
00106 #  define __ATTR_PURE__  __attribute__((__pure__))
00107 # endif
00108 #endif
00109 
00110 /** \def EEMEM
00111     \ingroup avr_eeprom
00112     Attribute expression causing a variable to be allocated within the
00113     .eeprom section.    */
00114 #define EEMEM __attribute__((section(".eeprom")))
00115 
00116 /** \def eeprom_is_ready
00117     \ingroup avr_eeprom
00118     \returns 1 if EEPROM is ready for a new read/write operation, 0 if not.
00119  */
00120 #if defined (__DOXYGEN__)
00121 # define eeprom_is_ready()
00122 #elif   defined (NVM_STATUS)
00123 # define eeprom_is_ready()  bit_is_clear (NVM_STATUS, NVM_NVMBUSY_bp)
00124 #elif   defined (NVMCTRL_STATUS)
00125 # define eeprom_is_ready()  bit_is_clear (NVMCTRL_STATUS, NVMCTRL_EEBUSY_bp)
00126 #elif   defined (DEECR)
00127 # define eeprom_is_ready()  bit_is_clear (DEECR, BSY)
00128 #elif   defined (EEPE)
00129 # define eeprom_is_ready()  bit_is_clear (EECR, EEPE)
00130 #else
00131 # define eeprom_is_ready()  bit_is_clear (EECR, EEWE)
00132 #endif
00133 
00134 
00135 /** \def eeprom_busy_wait
00136     \ingroup avr_eeprom
00137     Loops until the eeprom is no longer busy.
00138     \returns Nothing.
00139  */      
00140 #define eeprom_busy_wait() do {} while (!eeprom_is_ready())
00141 
00142 
00143 /** \ingroup avr_eeprom
00144     Read one byte from EEPROM address \a __p.
00145  */
00146 uint8_t eeprom_read_byte (const uint8_t *__p) __ATTR_PURE__;
00147 
00148 /** \ingroup avr_eeprom
00149     Read one 16-bit word (little endian) from EEPROM address \a __p.
00150  */
00151 uint16_t eeprom_read_word (const uint16_t *__p) __ATTR_PURE__;
00152 
00153 /** \ingroup avr_eeprom
00154     Read one 32-bit double word (little endian) from EEPROM address \a __p.
00155  */
00156 uint32_t eeprom_read_dword (const uint32_t *__p) __ATTR_PURE__;
00157 
00158 /** \ingroup avr_eeprom
00159     Read one float value (little endian) from EEPROM address \a __p.
00160  */
00161 float eeprom_read_float (const float *__p) __ATTR_PURE__;
00162 
00163 /** \ingroup avr_eeprom
00164     Read a block of \a __n bytes from EEPROM address \a __src to SRAM
00165     \a __dst.
00166  */
00167 void eeprom_read_block (void *__dst, const void *__src, size_t __n);
00168 
00169 
00170 /** \ingroup avr_eeprom
00171     Write a byte \a __value to EEPROM address \a __p.
00172  */
00173 void eeprom_write_byte (uint8_t *__p, uint8_t __value);
00174 
00175 /** \ingroup avr_eeprom
00176     Write a word \a __value to EEPROM address \a __p.
00177  */
00178 void eeprom_write_word (uint16_t *__p, uint16_t __value);
00179 
00180 /** \ingroup avr_eeprom
00181     Write a 32-bit double word \a __value to EEPROM address \a __p.
00182  */
00183 void eeprom_write_dword (uint32_t *__p, uint32_t __value);
00184 
00185 /** \ingroup avr_eeprom
00186     Write a float \a __value to EEPROM address \a __p.
00187  */
00188 void eeprom_write_float (float *__p, float __value);
00189 
00190 /** \ingroup avr_eeprom
00191     Write a block of \a __n bytes to EEPROM address \a __dst from \a __src.
00192     \note The argument order is mismatch with common functions like strcpy().
00193  */
00194 void eeprom_write_block (const void *__src, void *__dst, size_t __n);
00195 
00196 
00197 /** \ingroup avr_eeprom
00198     Update a byte \a __value to EEPROM address \a __p.
00199  */
00200 void eeprom_update_byte (uint8_t *__p, uint8_t __value);
00201 
00202 /** \ingroup avr_eeprom
00203     Update a word \a __value to EEPROM address \a __p.
00204  */
00205 void eeprom_update_word (uint16_t *__p, uint16_t __value);
00206 
00207 /** \ingroup avr_eeprom
00208     Update a 32-bit double word \a __value to EEPROM address \a __p.
00209  */
00210 void eeprom_update_dword (uint32_t *__p, uint32_t __value);
00211 
00212 /** \ingroup avr_eeprom
00213     Update a float \a __value to EEPROM address \a __p.
00214  */
00215 void eeprom_update_float (float *__p, float __value);
00216 
00217 /** \ingroup avr_eeprom
00218     Update a block of \a __n bytes to EEPROM address \a __dst from \a __src.
00219     \note The argument order is mismatch with common functions like strcpy().
00220  */
00221 void eeprom_update_block (const void *__src, void *__dst, size_t __n);
00222 
00223 
00224 /** \name IAR C compatibility defines   */
00225 /*@{*/
00226 
00227 /** \def _EEPUT
00228     \ingroup avr_eeprom
00229     Write a byte to EEPROM. Compatibility define for IAR C. */
00230 #define _EEPUT(addr, val) eeprom_write_byte ((uint8_t *)(addr), (uint8_t)(val))
00231 
00232 /** \def __EEPUT
00233     \ingroup avr_eeprom
00234     Write a byte to EEPROM. Compatibility define for IAR C. */
00235 #define __EEPUT(addr, val) eeprom_write_byte ((uint8_t *)(addr), (uint8_t)(val))
00236 
00237 /** \def _EEGET
00238     \ingroup avr_eeprom
00239     Read a byte from EEPROM. Compatibility define for IAR C.    */
00240 #define _EEGET(var, addr) (var) = eeprom_read_byte ((const uint8_t *)(addr))
00241 
00242 /** \def __EEGET
00243     \ingroup avr_eeprom
00244     Read a byte from EEPROM. Compatibility define for IAR C.    */
00245 #define __EEGET(var, addr) (var) = eeprom_read_byte ((const uint8_t *)(addr))
00246 
00247 /*@}*/
00248 
00249 #ifdef __cplusplus
00250 }
00251 #endif
00252 
00253 #endif  /* !__ASSEMBLER__ */
00254 #endif  /* E2END || defined(__DOXYGEN__) || defined(__COMPILING_AVR_LIBC__) */
00255 #endif  /* !_AVR_EEPROM_H_ */
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