Meanings about DSP2803x_Headers_nonBIOS.cmd

Yanbin Zhao92331 said:

I'm wondering about the meanings of these declarations in DSP2803x_Headers_nonBIOS.cmd:

/*** PIE Vect Table and Boot ROM Variables Structures ***/
  UNION run = PIE_VECT, PAGE = 1
   {
      PieVectTableFile
      GROUP
      {
         EmuKeyVar
         EmuBModeVar
         FlashCallbackVar
         FlashScalingVar
      }
   }

And following the above decleration is the memory map for register structures.

I wonder what does "UNION" keyword mean? And keyword "run" as well?

Are there any mannul for CMD files that I can refered to?

The command files are described in the assembler reference manual www.ti.com/lit/spru513

Cheers

Lori

Hi, Lori:

Thank you for your useful information.

I found in spru513:

"A NOLOAD section differs from a normal output section in one respect: its contents, relocation information, and line-number information are not placed in the output module. The linker allocates space for the section, and it appears in the memory-map listing."

And in official cmd file "F28035.cmd", the IQMathTables section are set as NOLOAD type.

I wonder if "its contents, relocation information, and line-number information are not placed in the output module", why should it be assembled in the output module? (especially that the contents is also not placed?)

Yanbin Zhao92331 said:

Hi, Lori:

Thank you for your useful information.

I found in spru513:

"A NOLOAD section differs from a normal output section in one respect: its contents, relocation information, and line-number information are not placed in the output module. The linker allocates space for the section, and it appears in the memory-map listing."

And in official cmd file "F28035.cmd", the IQMathTables section are set as NOLOAD type.

I wonder if "its contents, relocation information, and line-number information are not placed in the output module", why should it be assembled in the output module? (especially that the contents is also not placed?)

Those tables are in the ROM of the device.  If you use them you need to know where they are - thus the address can be included.  The tables are in ROM so they do not need to be loaded by the application since they already exist.