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请教GCCAVR如何定义外部RAM? |
作者:电子白菜 栏目:单片机 |
如果要指定位置的是不是: *(volatile unsigned CHAR *)(0x1234)=0xff; 这样可以吗: volatile unsigned CHAR * pRam; pRam=0x1234; *pRam=0x55; //以上这样好象GCC警告了:( 这样呢: volatile unsigned CHAR a; a=1; |
2楼: | >>参与讨论 |
作者: qjy_dali 于 2004/12/28 20:26:00 发布:
我不是很清楚,但有点印象 请去看WINAVR提供的MFILE程序,它用来产生MAKEFILE,在它的例子中,好像有关于外部SRAM的设置。 # Hey Emacs, this is a -*- makefile -*- # # WinAVR SAMPLE makefile written by Eric B. Weddington, J鰎g Wunsch, et al. # Released to the Public Domain # Please read the make user manual! # # Additional material for this makefile was submitted by: # Tim Henigan # Peter Fleury # Reiner Patommel # Sander Pool # Frederik Rouleau # Markus Pfaff # # On command LINE: # # make all = Make SOFTWARE. # # make clean = Clean out built project files. # # make coff = Convert ELF to AVR COFF (for use with AVR Studio 3.x or VMLAB). # # make extcoff = Convert ELF to AVR Extended COFF (for use with AVR Studio # 4.07 or greater). # # make program = Download the hex file to the DEVICE, using avrdude. Please # customize the avrdude settings below first! # # make fileNAME.s = Just compile fileNAME.c into the assembler code ONLY # # To rebuild project do "make clean" then "make all". # # MCU NAME MCU = ATMEGA128 # OUTPUT format. (can be srec, ihex, binary) FORMAT = ihex # Target file NAME (without extension). TARGET = main # List C source files here. (C dependencies are automatically generated.) SRC = $(TARGET).c # List Assembler source files here. # Make them always end in a capital .S. Files ending in a lowercase .s # will not be considered source files but generated files (assembler # OUTPUT from the compiler), and will be deleted upon "make clean"! # Even though the DOS/Win* filesystem matches both .s and .S the same, # it will preserve the spelling of the fileNAMEs, and gcc itself does # care about how the NAME is spelled on its command-LINE. ASRC = # Optimization level, can be [0, 1, 2, 3, s]. # 0 = turn off optimization. s = optimize for size. # (Note: 3 is not always the best optimization level. See avr-libc FAQ.) OPT = s # List any extra directories to look for include files here. # Each directory must be seperated by a space. EXTRAINCDIRS = # Compiler flag to set the C STANDARD level. # c89 - "ANSI" C # gnu89 - c89 plus GCC extensions # c99 - ISO C99 STANDARD (not yet fully implemented) # gnu99 - c99 plus GCC extensions CSTANDARD = -std=gnu99 # Place -D or -U options here CDEFS = # Place -I options here CINCS = # Compiler flags. # -g: generate debugging information # -O*: optimization level # -f...: tuning, see GCC manual and avr-libc documentation # -Wall...: warning level # -Wa,...: tell GCC to pass this to the assembler. # -adhlns...: create assembler listing CFLAGS = -g CFLAGS += $(CDEFS) $(CINCS) CFLAGS += -O$(OPT) CFLAGS += -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums CFLAGS += -Wall -Wstrict-prototypes CFLAGS += -Wa,-adhlns=$(<:.c=.lst) CFLAGS += $(patsubst %,-I%,$(EXTRAINCDIRS)) CFLAGS += $(CSTANDARD) # Assembler flags. # -Wa,...: tell GCC to pass this to the assembler. # -ahlms: create listing # -gstabs: have the assembler create LINE NUMBER information; note that # for use in COFF files, additional information about fileNAMEs # and function NAMEs needs to be present in the assembler source # files -- see avr-libc docs [FIXME: not yet described there] ASFLAGS = -Wa,-adhlns=$(<:.S=.lst),-gstabs #Additional libraries. # Minimalistic printf version PRINTF_LIB_MIN = -Wl,-u,vfprintf -lprintf_min # Floating point printf version (requires MATH_LIB = -lm below) PRINTF_LIB_FLOAT = -Wl,-u,vfprintf -lprintf_flt PRINTF_LIB = # Minimalistic scanf version SCANF_LIB_MIN = -Wl,-u,vfscanf -lscanf_min # Floating point + %[ scanf version (requires MATH_LIB = -lm below) SCANF_LIB_FLOAT = -Wl,-u,vfscanf -lscanf_flt SCANF_LIB = MATH_LIB = -lm #-------------------------------------------- # 我想这里应该是外部SRAM的设置吧? #-------------------------------------------- # External MEMORY options # 64 KB of external RAM, starting after internal RAM (ATMEGA128!), # used for variables (.data/.bss) and heap (malloc()). #EXTMEMOPTS = -Wl,-Tdata=0x801100,--defsym=__heap_end=0x80ffff # 64 KB of external RAM, starting after internal RAM (ATMEGA128!), # ONLY used for heap (malloc()). #EXTMEMOPTS = -Wl,--defsym=__heap_start=0x801100,--defsym=__heap_end=0x80ffff EXTMEMOPTS = # Linker flags. # -Wl,...: tell GCC to pass this to linker. # -Map: create map file # --cref: add cross reference to map file LDFLAGS = -Wl,-Map=$(TARGET).map,--cref LDFLAGS += $(EXTMEMOPTS) LDFLAGS += $(PRINTF_LIB) $(SCANF_LIB) $(MATH_LIB) # PROGRAMMING SUPPORT using avrdude. Settings and variables. # PROGRAMMING HARDWARE: alf avr910 AVRISP bascom bsd # dt006 pavr picoweb pony-stk200 SP12 stk200 STK500 # # Type: avrdude -c ? # to get a full listing. # AVRDUDE_PROGRAMMER = STK500 # com1 = serial port. Use lpt1 to connect to parallel port. AVRDUDE_PORT = com1 # programmer connected to serial DEVICE AVRDUDE_WRITE_FLASH = -U FLASH:w:$(TARGET).hex #AVRDUDE_WRITE_EEPROM = -U EEPROM:w:$(TARGET).eep # Uncomment the following if you want avrdude's erase cycle counter. # Note that this counter needs to be initialized first using -Yn, # see avrdude manual. #AVRDUDE_ERASE_COUNTER = -y # Uncomment the following if you do /not/ wish a verification to be # performed after PROGRAMMING the DEVICE. #AVRDUDE_NO_VERIFY = -V # Increase verbosity level. Please use this when submitting bug # reports about avrdude. See <http://savannah.nongnu.org/projects/avrdude> # to submit bug reports. #AVRDUDE_VERBOSE = -v -v AVRDUDE_FLAGS = -p $(MCU) -P $(AVRDUDE_PORT) -c $(AVRDUDE_PROGRAMMER) AVRDUDE_FLAGS += $(AVRDUDE_NO_VERIFY) AVRDUDE_FLAGS += $(AVRDUDE_VERBOSE) AVRDUDE_FLAGS += $(AVRDUDE_ERASE_COUNTER) # --------------------------------------------------------------------------- # Define directories, if needed. DIRAVR = c:/winavr DIRAVRBIN = $(DIRAVR)/bin DIRAVRUTILS = $(DIRAVR)/utils/bin DIRINC = . DIRLIB = $(DIRAVR)/avr/lib # Define programs and commands. SHELL = sh CC = avr-gcc OBJCOPY = avr-objcopy OBJDUMP = avr-objdump SIZE = avr-size NM = avr-nm AVRDUDE = avrdude REMOVE = rm -f COPY = cp # Define Messages # English MSG_ERRORS_NONE = Errors: n |
3楼: | >>参与讨论 |
作者: 电子白菜 于 2004/12/29 10:57:00 发布:
那是不是要定义了才能用volatile呢? 以前用ICC的时候就是直接volatile就可以的了。 |
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