If you haven't figured it out already, there are
some significant differences in running from external ram, and internal
flash. In theory, the stationary should shield you from those to a large
extent. Hoewever, the only way to fully understand what your code is
doing, is to understand the linker.cmd file for both
environments.
If you are not using the SDK, you will need to make
sure you are getting the reset "ISR" vector that is stored to program memory
address 0x0000 in the external ram version, to be stored at address 0x8000
(for 805 cpu) when the program runs from flash. The linker.cmd file
controls where the various chunks of code get located into either Ram or
Flash. In flash mode, the reset vector is always executed from the boot
flash memory, even though the address is still at program location zero.
The first 4 words of boot flash memory are mirrored into locations 0-3
in program memory space. I normally do this with 2 seperate
executables. The boot loader code, and the application
code.
Once you get the right vector at location zero, your
code should then run as it did from external ram.
One other point, if the above is correct, is to be
aware that when running from external ram, the download process may be
initializing your data. When running from Flash, without the benefit
of downloading each time, your code must initialize your data. This
is normally done by the the SDK architecture
code.
Hope this helps!!
Jerry
hi to all, i'm using
DSP56805EVM, i'm using project stationary & assembler
of codewarrior ver4.1.At present my codes r running from external memory
& now i want to run those codes from internal memory. For that i have
done the following 1)i hv removed JG8(sram enable)jumper. 2)i have
closed JG7(int/ext boot jumper),then downloaded the code to DSP via
parallel cable i.e. through JTAG port.
but my code
is not running. can anyone plz help me out Thanks in
advance
with regards
Virendra
singh
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