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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: eeprom.h 2468 2015-02-25 12:53:38Z pitchumani $ */
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 #ifndef __ASSEMBLER__
00049 
00050 #include <stddef.h> /* size_t */
00051 #include <stdint.h>
00052 
00053 /** \defgroup avr_eeprom <avr/eeprom.h>: EEPROM handling
00054     \code #include <avr/eeprom.h> \endcode
00055 
00056     This header file declares the interface to some simple library
00057     routines suitable for handling the data EEPROM contained in the
00058     AVR microcontrollers.  The implementation uses a simple polled
00059     mode interface.  Applications that require interrupt-controlled
00060     EEPROM access to ensure that no time will be wasted in spinloops
00061     will have to deploy their own implementation.
00062 
00063     \par Notes:
00064 
00065     - In addition to the write functions there is a set of update ones.
00066     This functions read each byte first and skip the burning if the
00067     old value is the same with new.  The scaning direction is from
00068     high address to low, to obtain quick return in common cases.
00069 
00070     - All of the read/write functions first make sure the EEPROM is
00071     ready to be accessed.  Since this may cause long delays if a
00072     write operation is still pending, time-critical applications
00073     should first poll the EEPROM e. g. using eeprom_is_ready() before
00074     attempting any actual I/O.  But this functions are not wait until
00075     SELFPRGEN in SPMCSR becomes zero.  Do this manually, if your
00076     softwate contains the Flash burning.
00077 
00078     - As these functions modify IO registers, they are known to be
00079     non-reentrant.  If any of these functions are used from both,
00080     standard and interrupt context, the applications must ensure
00081     proper protection (e.g. by disabling interrupts before accessing
00082     them).
00083 
00084     - All write functions force erase_and_write programming mode.
00085     
00086     - For Xmega the EEPROM start address is 0, like other architectures.
00087     The reading functions add the 0x2000 value to use EEPROM mapping into
00088     data space.
00089  */
00090 
00091 #ifdef __cplusplus
00092 extern "C" {
00093 #endif
00094 
00095 #ifndef __ATTR_PURE__
00096 # ifdef  __DOXYGEN__
00097 #  define __ATTR_PURE__
00098 # else
00099 #  define __ATTR_PURE__  __attribute__((__pure__))
00100 # endif
00101 #endif
00102 
00103 /** \def EEMEM
00104     \ingroup avr_eeprom
00105     Attribute expression causing a variable to be allocated within the
00106     .eeprom section.    */
00107 #define EEMEM __attribute__((section(".eeprom")))
00108 
00109 /** \def eeprom_is_ready
00110     \ingroup avr_eeprom
00111     \returns 1 if EEPROM is ready for a new read/write operation, 0 if not.
00112  */
00113 #if defined (__DOXYGEN__)
00114 # define eeprom_is_ready()
00115 #elif   defined (__AVR_XMEGA__) && __AVR_XMEGA__
00116 # define eeprom_is_ready()  bit_is_clear (NVM_STATUS, NVM_NVMBUSY_bp)
00117 #elif   defined (DEECR)
00118 # define eeprom_is_ready()  bit_is_clear (DEECR, BSY)
00119 #elif   defined (EEPE)
00120 # define eeprom_is_ready()  bit_is_clear (EECR, EEPE)
00121 #else
00122 # define eeprom_is_ready()  bit_is_clear (EECR, EEWE)
00123 #endif
00124 
00125 
00126 /** \def eeprom_busy_wait
00127     \ingroup avr_eeprom
00128     Loops until the eeprom is no longer busy.
00129     \returns Nothing.
00130  */      
00131 #define eeprom_busy_wait() do {} while (!eeprom_is_ready())
00132 
00133 
00134 /** \ingroup avr_eeprom
00135     Read one byte from EEPROM address \a __p.
00136  */
00137 uint8_t eeprom_read_byte (const uint8_t *__p) __ATTR_PURE__;
00138 
00139 /** \ingroup avr_eeprom
00140     Read one 16-bit word (little endian) from EEPROM address \a __p.
00141  */
00142 uint16_t eeprom_read_word (const uint16_t *__p) __ATTR_PURE__;
00143 
00144 /** \ingroup avr_eeprom
00145     Read one 32-bit double word (little endian) from EEPROM address \a __p.
00146  */
00147 uint32_t eeprom_read_dword (const uint32_t *__p) __ATTR_PURE__;
00148 
00149 /** \ingroup avr_eeprom
00150     Read one float value (little endian) from EEPROM address \a __p.
00151  */
00152 float eeprom_read_float (const float *__p) __ATTR_PURE__;
00153 
00154 /** \ingroup avr_eeprom
00155     Read a block of \a __n bytes from EEPROM address \a __src to SRAM
00156     \a __dst.
00157  */
00158 void eeprom_read_block (void *__dst, const void *__src, size_t __n);
00159 
00160 
00161 /** \ingroup avr_eeprom
00162     Write a byte \a __value to EEPROM address \a __p.
00163  */
00164 void eeprom_write_byte (uint8_t *__p, uint8_t __value);
00165 
00166 /** \ingroup avr_eeprom
00167     Write a word \a __value to EEPROM address \a __p.
00168  */
00169 void eeprom_write_word (uint16_t *__p, uint16_t __value);
00170 
00171 /** \ingroup avr_eeprom
00172     Write a 32-bit double word \a __value to EEPROM address \a __p.
00173  */
00174 void eeprom_write_dword (uint32_t *__p, uint32_t __value);
00175 
00176 /** \ingroup avr_eeprom
00177     Write a float \a __value to EEPROM address \a __p.
00178  */
00179 void eeprom_write_float (float *__p, float __value);
00180 
00181 /** \ingroup avr_eeprom
00182     Write a block of \a __n bytes to EEPROM address \a __dst from \a __src.
00183     \note The argument order is mismatch with common functions like strcpy().
00184  */
00185 void eeprom_write_block (const void *__src, void *__dst, size_t __n);
00186 
00187 
00188 /** \ingroup avr_eeprom
00189     Update a byte \a __value to EEPROM address \a __p.
00190  */
00191 void eeprom_update_byte (uint8_t *__p, uint8_t __value);
00192 
00193 /** \ingroup avr_eeprom
00194     Update a word \a __value to EEPROM address \a __p.
00195  */
00196 void eeprom_update_word (uint16_t *__p, uint16_t __value);
00197 
00198 /** \ingroup avr_eeprom
00199     Update a 32-bit double word \a __value to EEPROM address \a __p.
00200  */
00201 void eeprom_update_dword (uint32_t *__p, uint32_t __value);
00202 
00203 /** \ingroup avr_eeprom
00204     Update a float \a __value to EEPROM address \a __p.
00205  */
00206 void eeprom_update_float (float *__p, float __value);
00207 
00208 /** \ingroup avr_eeprom
00209     Update a block of \a __n bytes to EEPROM address \a __dst from \a __src.
00210     \note The argument order is mismatch with common functions like strcpy().
00211  */
00212 void eeprom_update_block (const void *__src, void *__dst, size_t __n);
00213 
00214 
00215 /** \name IAR C compatibility defines   */
00216 /*@{*/
00217 
00218 /** \def _EEPUT
00219     \ingroup avr_eeprom
00220     Write a byte to EEPROM. Compatibility define for IAR C. */
00221 #define _EEPUT(addr, val) eeprom_write_byte ((uint8_t *)(addr), (uint8_t)(val))
00222 
00223 /** \def __EEPUT
00224     \ingroup avr_eeprom
00225     Write a byte to EEPROM. Compatibility define for IAR C. */
00226 #define __EEPUT(addr, val) eeprom_write_byte ((uint8_t *)(addr), (uint8_t)(val))
00227 
00228 /** \def _EEGET
00229     \ingroup avr_eeprom
00230     Read a byte from EEPROM. Compatibility define for IAR C.    */
00231 #define _EEGET(var, addr) (var) = eeprom_read_byte ((const uint8_t *)(addr))
00232 
00233 /** \def __EEGET
00234     \ingroup avr_eeprom
00235     Read a byte from EEPROM. Compatibility define for IAR C.    */
00236 #define __EEGET(var, addr) (var) = eeprom_read_byte ((const uint8_t *)(addr))
00237 
00238 /*@}*/
00239 
00240 #ifdef __cplusplus
00241 }
00242 #endif
00243 
00244 #endif  /* !__ASSEMBLER__ */
00245 #endif  /* E2END || defined(__DOXYGEN__) || defined(__COMPILING_AVR_LIBC__) */
00246 #endif  /* !_AVR_EEPROM_H_ */
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