| /* Copyright (c) 2009 Dmitry Xmelkov |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are met: |
| |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in |
| the documentation and/or other materials provided with the |
| distribution. |
| * Neither the name of the copyright holders nor the names of |
| contributors may be used to endorse or promote products derived |
| from this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| POSSIBILITY OF SUCH DAMAGE. */ |
| |
| /* $Id: eerd_byte.S 1979 2009-06-05 23:08:14Z dmix $ */ |
| |
| #ifndef __DOXYGEN__ |
| |
| #include <avr/io.h> |
| |
| #if E2END && __AVR_ARCH__ > 1 |
| |
| #include <avr/eeprom.h> |
| #include "asmdef.h" |
| #include "eedef.h" |
| |
| /* uint8_t eeprom_read_byte (uint8_t EEMEM *addr); |
| */ |
| |
| #define ret_lo r24 |
| #define ret_hi r25 |
| |
| ENTRY eeprom_read_byte |
| |
| #if __AVR_XMEGA__ /* -------------------------------------------- */ |
| |
| rcall eeprom_mapen |
| ld ret_lo, Z |
| clr ret_hi |
| ret |
| |
| ENTRY eeprom_mapen |
| |
| ; Load base address of NVM. |
| ldi ZL, lo8(NVM_BASE) |
| ldi ZH, hi8(NVM_BASE) |
| |
| ; Wait until NVM is not busy. |
| 1: ldd r19, Z + NVM_STATUS - NVM_BASE |
| sbrc r19, NVM_NVMBUSY_bp |
| rjmp 1b |
| |
| ; Enable EEPROM mapping into data space. |
| ldd r19, Z + NVM_CTRLB - NVM_BASE |
| ori r19, NVM_EEMAPEN_bm |
| std Z + NVM_CTRLB - NVM_BASE, r19 |
| |
| ; Load Z with correct EEPROM address to read from data space. |
| movw ZL, addr_lo |
| subi ZL, lo8(-MAPPED_EEPROM_START) |
| sbci ZH, hi8(-MAPPED_EEPROM_START) |
| |
| ret |
| |
| #else /* -------------------------------------------- */ |
| |
| 1: sbic _SFR_IO_ADDR (EECR), EEWE |
| rjmp 1b |
| # ifdef EEARH |
| # if E2END > 0xFF |
| out _SFR_IO_ADDR (EEARH), addr_hi |
| # else |
| ; This is for chips like ATmega48: the EEAR8 bit must be cleaned. |
| out _SFR_IO_ADDR (EEARH), __zero_reg__ |
| # endif |
| # endif |
| out _SFR_IO_ADDR (EEARL), addr_lo |
| sbi _SFR_IO_ADDR (EECR), EERE |
| clr ret_hi |
| in ret_lo, _SFR_IO_ADDR (EEDR) |
| ret |
| |
| #endif /* -------------------------------------------- */ |
| |
| ENDFUNC |
| |
| #endif /* E2END && __AVR_ARCH__ > 1 */ |
| #endif /* !__DOXYGEN__ */ |