hI EVERYONE, There is a funciton of "AT91F_LowLevelInit()" in Cstartup_SAM7.c. Do I have to call this function in the beginning of my main() function? I tried the two condition and can not tell the difference. Min Ge
Guest
#1171404
Min Ge wrote: > There is a funciton of "AT91F_LowLevelInit()" in Cstartup_SAM7.c. > Do I have to call this function in the beginning of my main() function? > > I tried the two condition and can not tell the difference. The function is used in the "Atmel-scheme" for startup-code. Atmel has choosen a method to separate the startup in an assembler-part and a C-part. This is rather convinient since as much as possible can be done in C (the "Keil-Method" is to implement the startup in Assembler). Additional the AT91-lib functions can be used. IRC the c-code sets up the watchdog, system-clock and parts of the AIC so it is prefered to call the function as early as possible. If you'd like to follow the Atmel-Method look into the assembler-Code of the examples which include a Cstartup.c. You will see at which stage the function is called. For own developments: remind that a temporary stack is set up before calling the c-Function, just use the examples as templates. Martin Thomas.
Martin Thomas wrote: > Min Ge wrote: >> There is a funciton of "AT91F_LowLevelInit()" in Cstartup_SAM7.c. >> Do I have to call this function in the beginning of my main() function? >> >> I tried the two condition and can not tell the difference. > > The function is used in the "Atmel-scheme" for startup-code. Atmel has > choosen a method to separate the startup in an assembler-part and a > C-part. This is rather convinient since as much as possible can be done > in C (the "Keil-Method" is to implement the startup in Assembler). > Additional the AT91-lib functions can be used. IRC the c-code sets up > the watchdog, system-clock and parts of the AIC so it is prefered to > call the function as early as possible. > > If you'd like to follow the Atmel-Method look into the assembler-Code of > the examples which include a Cstartup.c. You will see at which stage the > function is called. For own developments: remind that a temporary stack > is set up before calling the c-Function, just use the examples as > templates. > > Martin Thomas. Thanks a lot. I got it. Min Ge