RTS Fast Math Supplement F28335

Nicholas,

Can you post the disassembly of that line generated by both the normal RTS lib and the FastRTS lib

I assume by disassembly you mean the assembler code?  This is from the .lst files which I got by using the –al compiler parameter.  I have done a diff on the files before and the only difference is the time they are generated.  The .map files change to include the faster functions from the FastRTS library, but it all looks OK. 

The line in question is line 1822, I have included some stuff before because that is where the other R0H register gets loaded.  I downloaded both the output files and the Fast RTS gives the error whilst the normal RTS doesn’t.  I should add that this function happens in the highest priority interrupt (only have one) so shouldn’t be interrupted in my opinion.

Here is the ASM code with the normal RTS Library:

    4355                      ; call occurs [#FS$$DIV] ; |1814|

    4356 00000d9c 761F-         MOVW      DP,#_mcu_skai2_B+796

         00000d9d 001B

    4357 00000d9e E203-         MOV32     @_mcu_skai2_B+796,R0H

         00000d9f 001C

    4358                      .dwpsn  file "mcu_skai2.c",line 1822,column 7,is_stmt

    4359 00000da0 E2AF-         MOV32     R1H,@_mcu_skai2_B+778

         00000da1 010A

    4360 00000da2 E720          SUBF32    R0H,R1H,R0H           ; |1822|

         00000da3 0008

    4361 00000da4 7700          NOP

    4362 00000da5 E203-         MOV32     @_mcu_skai2_B+798,R0H

        00000da6 001E

And here it is with the Fast RTS Library :

4355                      ; call occurs [#FS$$DIV] ; |1814|

    4356 00000d9c 761F-         MOVW      DP,#_mcu_skai2_B+796

         00000d9d 001B

    4357 00000d9e E203-         MOV32     @_mcu_skai2_B+796,R0H

         00000d9f 001C

    4358                      .dwpsn  file "mcu_skai2.c",line 1822,column 7,is_stmt

    4359 00000da0 E2AF-         MOV32     R1H,@_mcu_skai2_B+778

         00000da1 010A

    4360 00000da2 E720          SUBF32    R0H,R1H,R0H           ; |1822|

         00000da3 0008

    4361 00000da4 7700          NOP

    4362 00000da5 E203-         MOV32     @_mcu_skai2_B+798,R0H

         00000da6 001E

I hope you can help

Nicholas,

The assembly is the same in both cases so Im thinking the variable mcu_skai2_B.max_flux_const never got initialized as there is no auto initialization function in the fastRTS so you have to include the normal RTS library in the project but there is an order of linking. Please check the doc for fastRTS on how to do it. You can find it in the controlSUITE folder: C:\TI\controlSUITE\libs\math\FPUfastRTS\V100\doc

Let me know if that solves the problem

Hi Vishal

I have already tried the linking order procedure specified in the FastRTS datasheet, the same thing happens.  mcu_skai2_B.max_flux_const is part of a struct that gets initialised during startup, it definitely has a value, I can read the values over CAN.

How can I view the post-linker assembler code?

Regards

Nicholas

When you launch debug, open up the disassembly view from the View menu option in the debug perspective to see the assembly instructions or

Is the value of const other than zero when you enter the interrupt or before the subtraction takes place?

Hi Vishal

I haven't had much time to work on this issue recently, I have been catching up on documentation.  I will look at the disassembly of the .out files when I get a chance.  The value of const is non-zero when entering the interrupt.

Regards

Nicholas