F28335 and maths library

Hi Vishal,

Thank you for your answer, we will try this library.

Another question related to this one : how to be sure to locate the maximum code in ramfuncs, to have the lowest CPU load possible? Indeed I saw that even by suppressing all the maths functions in my model, I still have CPU load problem when working in Flash, so I suppose that even using this new library I will still have the problem.

Which other files can I locate in ramfuncs ? In attached file you will find my .map file, in case it cans help you.

Best regards,

Julien

Hi Julien,

didnt find any attachment. You could, if you wanted to, dump the entire .text section from all .obj files into ramfuncs like you did with the math lib and have your entire code run out of RAM. Its not possible to tell from the .map what sections of code are loading the CPU more or less than any other section. You are going to have to identify code that runs frequently and put those in ramfuncs.

Also, the flash has waitstates associated with it. You may not be running with the best possible wait state. Im not the expert on that but im pretty sure its documented in the flash or system control chapter in the TRM on how to optimize the wait-states

Hello,

I tried to dump all the .text section into ramfuncs by doing this :

    ramfuncs:     LOAD = FLASH,
        RUN = RAML4L7,
        LOAD_START(_RamfuncsLoadStart),
        LOAD_END(_RamfuncsLoadEnd),
        RUN_START(_RamfuncsRunStart),
        PAGE = 0
                 {
                   *.obj (.text)                   
                   -l rts2800_fpu32.lib<sin.obj sqrt.obj modf.obj fmod.obj fs_div.obj memcpy_ff.obj memset.obj> (.text)
                 }

Thus, I am able to compile and flash the DSP, but then the DSP does not start (no LED flashing, no CAN communication). Is it normal ? Are there any .obj that we should not dump into ramfuncs?

Then, what is the syntax if I want to dump a specific .obj file into ramfuncs (for example MW_c28xx_pwm.obj) : I tried "MW_c28xx_pwm.obj (.text)" but doing so the link fails.

Best regards,

Julien

Also as to the syntax of dumping sections from .obj files, what you wrote doe work, i tried the following

   ramfuncs        :  LOAD = FLASHC,
                      RUN = RAMLS1,
                      RUN_START(_RamfuncsRunStart),
                      LOAD_START(_RamfuncsLoadStart),
                      LOAD_SIZE(_RamfuncsLoadSize),
                      PAGE = 0
                      {
                        main.obj(.text)
                       }

in the map file i see

ramfuncs   0    00084000    000000e6     RUN ADDR = 00008800
                  00084000    00000093     main.obj (.text)
                  00084093    0000004f     main.obj (.text:retain)
                  000840e2    00000004     driverlib.lib : sysctl.obj (ramfuncs)

If foo is not a user-defined function, but a function in a LIB library, such as InstaSPIN_BLDC in InstaSPIN-BLDC, will # pragma CODE_SECTION (InstaSPIN_BLDC, "ramfuncs") be useful? I found that I did not succeed in moving InstaSPIN_BLDC into ramfuncs;